diff --git a/src/base/utils/fs.cpp b/src/base/utils/fs.cpp
index ae0ed75ee..fe9717078 100644
--- a/src/base/utils/fs.cpp
+++ b/src/base/utils/fs.cpp
@@ -292,6 +292,12 @@ bool Utils::Fs::isNetworkFileSystem(const Path &path)
 
 bool Utils::Fs::copyFile(const Path &from, const Path &to)
 {
+    if (!from.exists())
+        return false;
+
+    if (!mkpath(to.parentPath()))
+        return false;
+
     return QFile::copy(from.data(), to.data());
 }
 
diff --git a/src/base/utils/io.cpp b/src/base/utils/io.cpp
index afb904930..b5c938efc 100644
--- a/src/base/utils/io.cpp
+++ b/src/base/utils/io.cpp
@@ -37,6 +37,7 @@
 #include <QString>
 
 #include "base/path.h"
+#include "base/utils/fs.h"
 
 Utils::IO::FileDeviceOutputIterator::FileDeviceOutputIterator(QFileDevice &device, const int bufferSize)
     : m_device {&device}
@@ -70,6 +71,8 @@ Utils::IO::FileDeviceOutputIterator &Utils::IO::FileDeviceOutputIterator::operat
 
 nonstd::expected<void, QString> Utils::IO::saveToFile(const Path &path, const QByteArray &data)
 {
+    if (const Path parentPath = path.parentPath(); !parentPath.isEmpty())
+        Utils::Fs::mkpath(parentPath);
     QSaveFile file {path.data()};
     if (!file.open(QIODevice::WriteOnly) || (file.write(data) != data.size()) || !file.flush() || !file.commit())
         return nonstd::make_unexpected(file.errorString());
diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index c98eb5d8a..443021a48 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -37,6 +37,7 @@ qt_wrap_ui(UI_HEADERS
     torrentcreatordialog.ui
     torrentoptionsdialog.ui
     trackerentriesdialog.ui
+    uithemedialog.ui
     watchedfolderoptionsdialog.ui
 )
 
@@ -121,7 +122,10 @@ add_library(qbt_gui STATIC
     transferlistwidget.h
     tristateaction.h
     tristatewidget.h
+    uithemecommon.h
+    uithemedialog.h
     uithememanager.h
+    uithemesource.h
     utils.h
     watchedfolderoptionsdialog.h
     watchedfoldersmodel.h
@@ -205,7 +209,9 @@ add_library(qbt_gui STATIC
     transferlistwidget.cpp
     tristateaction.cpp
     tristatewidget.cpp
+    uithemedialog.cpp
     uithememanager.cpp
+    uithemesource.cpp
     utils.cpp
     watchedfolderoptionsdialog.cpp
     watchedfoldersmodel.cpp
diff --git a/src/gui/color.h b/src/gui/color.h
index 7438f91e0..9859e19fc 100644
--- a/src/gui/color.h
+++ b/src/gui/color.h
@@ -28,6 +28,8 @@
 
 #pragma once
 
+#include <QColor>
+
 namespace Color
 {
     /*
diff --git a/src/gui/gui.pri b/src/gui/gui.pri
index a07251a8a..f41193456 100644
--- a/src/gui/gui.pri
+++ b/src/gui/gui.pri
@@ -80,7 +80,10 @@ HEADERS += \
     $$PWD/transferlistwidget.h \
     $$PWD/tristateaction.h \
     $$PWD/tristatewidget.h \
+    $$PWD/uithemecommon.h \
+    $$PWD/uithemedialog.h \
     $$PWD/uithememanager.h \
+    $$PWD/uithemesource.h \
     $$PWD/utils.h \
     $$PWD/watchedfolderoptionsdialog.h \
     $$PWD/watchedfoldersmodel.h \
@@ -164,7 +167,9 @@ SOURCES += \
     $$PWD/transferlistwidget.cpp \
     $$PWD/tristateaction.cpp \
     $$PWD/tristatewidget.cpp \
+    $$PWD/uithemedialog.cpp \
     $$PWD/uithememanager.cpp \
+    $$PWD/uithemesource.cpp \
     $$PWD/utils.cpp \
     $$PWD/watchedfolderoptionsdialog.cpp \
     $$PWD/watchedfoldersmodel.cpp
@@ -198,6 +203,7 @@ FORMS += \
     $$PWD/torrentcreatordialog.ui \
     $$PWD/torrentoptionsdialog.ui \
     $$PWD/trackerentriesdialog.ui \
+    $$PWD/uithemedialog.ui \
     $$PWD/watchedfolderoptionsdialog.ui
 
 RESOURCES += $$PWD/about.qrc
diff --git a/src/gui/optionsdialog.cpp b/src/gui/optionsdialog.cpp
index 96b0817d8..3f61856b9 100644
--- a/src/gui/optionsdialog.cpp
+++ b/src/gui/optionsdialog.cpp
@@ -63,6 +63,7 @@
 #include "ipsubnetwhitelistoptionsdialog.h"
 #include "rss/automatedrssdownloader.h"
 #include "ui_optionsdialog.h"
+#include "uithemedialog.h"
 #include "uithememanager.h"
 #include "utils.h"
 #include "watchedfolderoptionsdialog.h"
@@ -323,6 +324,18 @@ void OptionsDialog::loadBehaviorTabOptions()
     connect(m_ui->checkUseCustomTheme, &QGroupBox::toggled, this, &ThisType::enableApplyButton);
     connect(m_ui->customThemeFilePath, &FileSystemPathEdit::selectedPathChanged, this, &ThisType::enableApplyButton);
 
+    m_ui->buttonCustomizeUITheme->setEnabled(!m_ui->checkUseCustomTheme->isChecked());
+    connect(m_ui->checkUseCustomTheme, &QGroupBox::toggled, this, [this]
+    {
+        m_ui->buttonCustomizeUITheme->setEnabled(!m_ui->checkUseCustomTheme->isChecked());
+    });
+    connect(m_ui->buttonCustomizeUITheme, &QPushButton::clicked, this, [this]
+    {
+        auto dialog = new UIThemeDialog(this);
+        dialog->setAttribute(Qt::WA_DeleteOnClose);
+        dialog->open();
+    });
+
     connect(m_ui->confirmDeletion, &QAbstractButton::toggled, this, &ThisType::enableApplyButton);
     connect(m_ui->checkAltRowColors, &QAbstractButton::toggled, this, &ThisType::enableApplyButton);
     connect(m_ui->checkHideZero, &QAbstractButton::toggled, m_ui->comboHideZero, &QWidget::setEnabled);
diff --git a/src/gui/optionsdialog.ui b/src/gui/optionsdialog.ui
index 9260af724..58e18f7ab 100644
--- a/src/gui/optionsdialog.ui
+++ b/src/gui/optionsdialog.ui
@@ -122,8 +122,8 @@
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>501</width>
-             <height>893</height>
+             <width>504</width>
+             <height>1064</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout_9">
@@ -133,7 +133,7 @@
                <string>Interface</string>
               </property>
               <layout class="QGridLayout" name="gridLayout_81">
-               <item row="0" column="0" colspan="2">
+               <item row="0" column="0" colspan="3">
                 <widget class="QLabel" name="label_15">
                  <property name="font">
                   <font>
@@ -210,6 +210,13 @@
                  </property>
                 </widget>
                </item>
+               <item row="4" column="0" colspan="2">
+                <widget class="QPushButton" name="buttonCustomizeUITheme">
+                 <property name="text">
+                  <string>Customize UI Theme...</string>
+                 </property>
+                </widget>
+               </item>
               </layout>
              </widget>
             </item>
@@ -778,8 +785,8 @@
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>591</width>
-             <height>1138</height>
+             <width>539</width>
+             <height>1457</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout">
@@ -1565,8 +1572,8 @@ readme[0-9].txt: filter 'readme1.txt', 'readme2.txt' but not 'readme10.txt'.</st
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>501</width>
-             <height>745</height>
+             <width>377</width>
+             <height>756</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout_20">
@@ -1800,7 +1807,7 @@ readme[0-9].txt: filter 'readme1.txt', 'readme2.txt' but not 'readme10.txt'.</st
                   </widget>
                  </item>
                  <item>
-                  <widget class="QComboBox" name="comboProxyType" />
+                  <widget class="QComboBox" name="comboProxyType"/>
                  </item>
                  <item>
                   <widget class="QLabel" name="lblProxyIP">
@@ -1810,7 +1817,7 @@ readme[0-9].txt: filter 'readme1.txt', 'readme2.txt' but not 'readme10.txt'.</st
                   </widget>
                  </item>
                  <item>
-                  <widget class="QLineEdit" name="textProxyIP" />
+                  <widget class="QLineEdit" name="textProxyIP"/>
                  </item>
                  <item>
                   <widget class="QLabel" name="lblProxyPort">
@@ -2056,8 +2063,8 @@ readme[0-9].txt: filter 'readme1.txt', 'readme2.txt' but not 'readme10.txt'.</st
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>516</width>
-             <height>525</height>
+             <width>302</width>
+             <height>408</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout_5">
@@ -2393,8 +2400,8 @@ readme[0-9].txt: filter 'readme1.txt', 'readme2.txt' but not 'readme10.txt'.</st
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>513</width>
-             <height>679</height>
+             <width>413</width>
+             <height>693</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout_7">
@@ -2913,8 +2920,8 @@ Disable encryption: Only connect to peers without protocol encryption</string>
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>516</width>
-             <height>525</height>
+             <width>336</width>
+             <height>391</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout_27">
@@ -3083,8 +3090,8 @@ Disable encryption: Only connect to peers without protocol encryption</string>
             <rect>
              <x>0</x>
              <y>0</y>
-             <width>501</width>
-             <height>636</height>
+             <width>382</width>
+             <height>1045</height>
             </rect>
            </property>
            <layout class="QVBoxLayout" name="verticalLayout_23">
diff --git a/src/gui/uithemecommon.h b/src/gui/uithemecommon.h
new file mode 100644
index 000000000..9f1a33192
--- /dev/null
+++ b/src/gui/uithemecommon.h
@@ -0,0 +1,181 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2023  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If
+ * you modify file(s), you may extend this exception to your version of the
+ * file(s), but you are not obligated to do so. If you do not wish to do so,
+ * delete this exception statement from your version.
+ */
+
+#pragma once
+
+#include <QtGlobal>
+#include <QApplication>
+#include <QColor>
+#include <QHash>
+#include <QPalette>
+#include <QSet>
+#include <QString>
+
+#include "base/global.h"
+#include "color.h"
+
+inline const QString CONFIG_FILE_NAME = u"config.json"_qs;
+inline const QString STYLESHEET_FILE_NAME = u"stylesheet.qss"_qs;
+inline const QString KEY_COLORS = u"colors"_qs;
+inline const QString KEY_COLORS_LIGHT = u"colors.light"_qs;
+inline const QString KEY_COLORS_DARK = u"colors.dark"_qs;
+
+struct UIThemeColor
+{
+    QColor light;
+    QColor dark;
+};
+
+inline QHash<QString, UIThemeColor> defaultUIThemeColors()
+{
+    const QPalette palette = QApplication::palette();
+    return {
+        {u"Log.TimeStamp"_qs, {Color::Primer::Light::fgSubtle, Color::Primer::Dark::fgSubtle}},
+        {u"Log.Normal"_qs, {palette.color(QPalette::Active, QPalette::WindowText), palette.color(QPalette::Active, QPalette::WindowText)}},
+        {u"Log.Info"_qs, {Color::Primer::Light::accentFg, Color::Primer::Dark::accentFg}},
+        {u"Log.Warning"_qs, {Color::Primer::Light::severeFg, Color::Primer::Dark::severeFg}},
+        {u"Log.Critical"_qs, {Color::Primer::Light::dangerFg, Color::Primer::Dark::dangerFg}},
+        {u"Log.BannedPeer"_qs, {Color::Primer::Light::dangerFg, Color::Primer::Dark::dangerFg}},
+
+        {u"RSS.ReadArticle"_qs, {palette.color(QPalette::Inactive, QPalette::WindowText), palette.color(QPalette::Inactive, QPalette::WindowText)}},
+        {u"RSS.UnreadArticle"_qs, {palette.color(QPalette::Active, QPalette::Link), palette.color(QPalette::Active, QPalette::Link)}},
+
+        {u"TransferList.Downloading"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.StalledDownloading"_qs, {Color::Primer::Light::successEmphasis, Color::Primer::Dark::successEmphasis}},
+        {u"TransferList.DownloadingMetadata"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.ForcedDownloadingMetadata"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.ForcedDownloading"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.Uploading"_qs, {Color::Primer::Light::accentFg, Color::Primer::Dark::accentFg}},
+        {u"TransferList.StalledUploading"_qs, {Color::Primer::Light::accentEmphasis, Color::Primer::Dark::accentEmphasis}},
+        {u"TransferList.ForcedUploading"_qs, {Color::Primer::Light::accentFg, Color::Primer::Dark::accentFg}},
+        {u"TransferList.QueuedDownloading"_qs, {Color::Primer::Light::scaleYellow6, Color::Primer::Dark::scaleYellow6}},
+        {u"TransferList.QueuedUploading"_qs, {Color::Primer::Light::scaleYellow6, Color::Primer::Dark::scaleYellow6}},
+        {u"TransferList.CheckingDownloading"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.CheckingUploading"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.CheckingResumeData"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.PausedDownloading"_qs, {Color::Primer::Light::fgMuted, Color::Primer::Dark::fgMuted}},
+        {u"TransferList.PausedUploading"_qs, {Color::Primer::Light::doneFg, Color::Primer::Dark::doneFg}},
+        {u"TransferList.Moving"_qs, {Color::Primer::Light::successFg, Color::Primer::Dark::successFg}},
+        {u"TransferList.MissingFiles"_qs, {Color::Primer::Light::dangerFg, Color::Primer::Dark::dangerFg}},
+        {u"TransferList.Error"_qs, {Color::Primer::Light::dangerFg, Color::Primer::Dark::dangerFg}}
+    };
+}
+
+inline QSet<QString> defaultUIThemeIcons()
+{
+    return {
+        u"application-exit"_qs,
+        u"application-rss"_qs,
+        u"application-url"_qs,
+        u"browser-cookies"_qs,
+        u"chart-line"_qs,
+        u"checked-completed"_qs,
+        u"configure"_qs,
+        u"connected"_qs,
+        u"dialog-warning"_qs,
+        u"directory"_qs,
+        u"disconnected"_qs,
+        u"download"_qs,
+        u"downloading"_qs,
+        u"edit-clear"_qs,
+        u"edit-copy"_qs,
+        u"edit-find"_qs,
+        u"edit-rename"_qs,
+        u"error"_qs,
+        u"fileicon"_qs,
+        u"filter-active"_qs,
+        u"filter-all"_qs,
+        u"filter-inactive"_qs,
+        u"filter-stalled"_qs,
+        u"firewalled"_qs,
+        u"folder-documents"_qs,
+        u"folder-new"_qs,
+        u"folder-remote"_qs,
+        u"force-recheck"_qs,
+        u"go-bottom"_qs,
+        u"go-down"_qs,
+        u"go-top"_qs,
+        u"go-up"_qs,
+        u"hash"_qs,
+        u"help-about"_qs,
+        u"help-contents"_qs,
+        u"insert-link"_qs,
+        u"ip-blocked"_qs,
+        u"list-add"_qs,
+        u"list-remove"_qs,
+        u"loading"_qs,
+        u"mail-inbox"_qs,
+        u"name"_qs,
+        u"network-connect"_qs,
+        u"network-server"_qs,
+        u"object-locked"_qs,
+        u"peers"_qs,
+        u"peers-add"_qs,
+        u"peers-remove"_qs,
+        u"plugins"_qs,
+        u"preferences-advanced"_qs,
+        u"preferences-bittorrent"_qs,
+        u"preferences-desktop"_qs,
+        u"preferences-webui"_qs,
+        u"qbittorrent-tray"_qs,
+        u"qbittorrent-tray-dark"_qs,
+        u"qbittorrent-tray-light"_qs,
+        u"queued"_qs,
+        u"ratio"_qs,
+        u"reannounce"_qs,
+        u"security-high"_qs,
+        u"security-low"_qs,
+        u"set-location"_qs,
+        u"slow"_qs,
+        u"slow_off"_qs,
+        u"speedometer"_qs,
+        u"stalledDL"_qs,
+        u"stalledUP"_qs,
+        u"stopped"_qs,
+        u"system-log-out"_qs,
+        u"tags"_qs,
+        u"task-complete"_qs,
+        u"task-reject"_qs,
+        u"torrent-creator"_qs,
+        u"torrent-magnet"_qs,
+        u"torrent-start"_qs,
+        u"torrent-start-forced"_qs,
+        u"torrent-stop"_qs,
+        u"tracker-error"_qs,
+        u"tracker-warning"_qs,
+        u"trackerless"_qs,
+        u"trackers"_qs,
+        u"upload"_qs,
+        u"view-categories"_qs,
+        u"view-preview"_qs,
+        u"view-refresh"_qs,
+        u"view-statistics"_qs,
+        u"wallet-open"_qs
+    };
+}
diff --git a/src/gui/uithemedialog.cpp b/src/gui/uithemedialog.cpp
new file mode 100644
index 000000000..d8bedb72a
--- /dev/null
+++ b/src/gui/uithemedialog.cpp
@@ -0,0 +1,388 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2023  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include "uithemedialog.h"
+
+#include <QColor>
+#include <QColorDialog>
+#include <QFile>
+#include <QFileDialog>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QLabel>
+#include <QMenu>
+#include <QMessageBox>
+
+#include "base/3rdparty/expected.hpp"
+#include "base/global.h"
+#include "base/logger.h"
+#include "base/path.h"
+#include "base/profile.h"
+#include "base/utils/fs.h"
+#include "base/utils/io.h"
+#include "uithemecommon.h"
+#include "utils.h"
+
+#include "ui_uithemedialog.h"
+
+namespace
+{
+    Path userConfigPath()
+    {
+        return specialFolderLocation(SpecialFolder::Config) / Path(u"themes/default"_qs);
+    }
+
+    Path defaultIconPath(const QString &iconID, [[maybe_unused]] const ColorMode colorMode)
+    {
+        return Path(u":icons"_qs) / Path(iconID + u".svg");
+    }
+}
+
+class ColorWidget final : public QFrame
+{
+    Q_DISABLE_COPY_MOVE(ColorWidget)
+
+public:
+    explicit ColorWidget(const QColor &currentColor, const QColor &defaultColor, QWidget *parent = nullptr)
+        : QFrame(parent)
+        , m_defaultColor {defaultColor}
+    {
+        setObjectName(u"colorWidget"_qs);
+        setFrameShape(QFrame::Box);
+        setFrameShadow(QFrame::Plain);
+
+        setCurrentColor(currentColor);
+    }
+
+    QColor currentColor() const
+    {
+        return m_currentColor;
+    }
+
+private:
+    void mouseDoubleClickEvent([[maybe_unused]] QMouseEvent *event) override
+    {
+        showColorDialog();
+    }
+
+    void contextMenuEvent([[maybe_unused]] QContextMenuEvent *event) override
+    {
+        QMenu *menu = new QMenu(this);
+        menu->setAttribute(Qt::WA_DeleteOnClose);
+
+        menu->addAction(tr("Edit..."), this, &ColorWidget::showColorDialog);
+        menu->addAction(tr("Reset"), this, &ColorWidget::resetColor);
+
+        menu->popup(QCursor::pos());
+    }
+
+    void setCurrentColor(const QColor &color)
+    {
+        if (m_currentColor == color)
+            return;
+
+        m_currentColor = color;
+        applyColor(m_currentColor);
+    }
+
+    void resetColor()
+    {
+        setCurrentColor(m_defaultColor);
+    }
+
+    void applyColor(const QColor &color)
+    {
+        setStyleSheet(u"#colorWidget { background-color: %1; }"_qs.arg(color.name()));
+    }
+
+    void showColorDialog()
+    {
+        auto dialog = new QColorDialog(m_currentColor, this);
+        dialog->setAttribute(Qt::WA_DeleteOnClose);
+        connect(dialog, &QDialog::accepted, this, [this, dialog]
+        {
+            setCurrentColor(dialog->currentColor());
+        });
+
+        dialog->open();
+    }
+
+    const QColor m_defaultColor;
+    QColor m_currentColor;
+};
+
+class IconWidget final : public QLabel
+{
+    Q_DISABLE_COPY_MOVE(IconWidget)
+
+public:
+    explicit IconWidget(const Path &currentPath, const Path &defaultPath, QWidget *parent = nullptr)
+        : QLabel(parent)
+        , m_defaultPath {defaultPath}
+    {
+        setObjectName(u"iconWidget"_qs);
+        setAlignment(Qt::AlignCenter);
+
+        setCurrentPath(currentPath);
+    }
+
+    Path currentPath() const
+    {
+        return m_currentPath;
+    }
+
+private:
+    void mouseDoubleClickEvent([[maybe_unused]] QMouseEvent *event) override
+    {
+        showFileDialog();
+    }
+
+    void contextMenuEvent([[maybe_unused]] QContextMenuEvent *event) override
+    {
+        QMenu *menu = new QMenu(this);
+        menu->setAttribute(Qt::WA_DeleteOnClose);
+
+        menu->addAction(tr("Browse..."), this, &IconWidget::showFileDialog);
+        menu->addAction(tr("Reset"), this, &IconWidget::resetIcon);
+
+        menu->popup(QCursor::pos());
+    }
+
+    void setCurrentPath(const Path &path)
+    {
+        if (m_currentPath == path)
+            return;
+
+        m_currentPath = path;
+        showIcon(m_currentPath);
+    }
+
+    void resetIcon()
+    {
+        setCurrentPath(m_defaultPath);
+    }
+
+    void showIcon(const Path &iconPath)
+    {
+        const QIcon icon {iconPath.data()};
+        setPixmap(icon.pixmap(Utils::Gui::smallIconSize()));
+    }
+
+    void showFileDialog()
+    {
+        auto *dialog = new QFileDialog(this, tr("Select icon")
+                , QDir::homePath(), (tr("Supported image files") + u" (*.svg *.png)"));
+        dialog->setFileMode(QFileDialog::ExistingFile);
+        dialog->setAttribute(Qt::WA_DeleteOnClose);
+        connect(dialog, &QDialog::accepted, this, [this, dialog]
+        {
+            const Path iconPath {dialog->selectedFiles().value(0)};
+            setCurrentPath(iconPath);
+        });
+
+        dialog->open();
+    }
+
+    const Path m_defaultPath;
+    Path m_currentPath;
+};
+
+UIThemeDialog::UIThemeDialog(QWidget *parent)
+    : QDialog(parent)
+    , m_ui {new Ui::UIThemeDialog}
+{
+    m_ui->setupUi(this);
+
+    loadColors();
+    loadIcons();
+}
+
+UIThemeDialog::~UIThemeDialog()
+{
+    delete m_ui;
+}
+
+void UIThemeDialog::accept()
+{
+    QDialog::accept();
+
+    bool hasError = false;
+    if (!storeColors())
+        hasError = true;
+    if (!storeIcons())
+        hasError = true;
+
+    if (hasError)
+    {
+        QMessageBox::critical(this, tr("UI Theme Configuration.")
+                , tr("The UI Theme changes could not be fully applied. The details can be found in the Log."));
+    }
+}
+
+void UIThemeDialog::loadColors()
+{
+    const QHash<QString, UIThemeColor> defaultColors = defaultUIThemeColors();
+    const QList<QString> colorIDs = std::invoke([](auto &&list) { list.sort(); return list; }, defaultColors.keys());
+    int row = 2;
+    for (const QString &id : colorIDs)
+    {
+        m_ui->colorsLayout->addWidget(new QLabel(id), row, 0);
+
+        const UIThemeColor &defaultColor = defaultColors.value(id);
+
+        auto *lightColorWidget = new ColorWidget(m_defaultThemeSource.getColor(id, ColorMode::Light), defaultColor.light, this);
+        m_lightColorWidgets.insert(id, lightColorWidget);
+        m_ui->colorsLayout->addWidget(lightColorWidget, row, 2);
+
+        auto *darkColorWidget = new ColorWidget(m_defaultThemeSource.getColor(id, ColorMode::Dark), defaultColor.dark, this);
+        m_darkColorWidgets.insert(id, darkColorWidget);
+        m_ui->colorsLayout->addWidget(darkColorWidget, row, 4);
+
+        ++row;
+    }
+}
+
+void UIThemeDialog::loadIcons()
+{
+    const QSet<QString> defaultIcons = defaultUIThemeIcons();
+    const QList<QString> iconIDs = std::invoke([](auto &&list) { list.sort(); return list; }
+            , QList<QString>(defaultIcons.cbegin(), defaultIcons.cend()));
+    int row = 2;
+    for (const QString &id : iconIDs)
+    {
+        m_ui->iconsLayout->addWidget(new QLabel(id), row, 0);
+
+        auto *lightIconWidget = new IconWidget(m_defaultThemeSource.getIconPath(id, ColorMode::Light)
+                , defaultIconPath(id, ColorMode::Light), this);
+        m_lightIconWidgets.insert(id, lightIconWidget);
+        m_ui->iconsLayout->addWidget(lightIconWidget, row, 2);
+
+        auto *darkIconWidget = new IconWidget(m_defaultThemeSource.getIconPath(id, ColorMode::Dark)
+                , defaultIconPath(id, ColorMode::Dark), this);
+        m_darkIconWidgets.insert(id, darkIconWidget);
+        m_ui->iconsLayout->addWidget(darkIconWidget, row, 4);
+
+        ++row;
+    }
+}
+
+bool UIThemeDialog::storeColors()
+{
+    QJsonObject userConfig;
+    userConfig.insert(u"version", 2);
+
+    const QHash<QString, UIThemeColor> defaultColors = defaultUIThemeColors();
+    const auto addColorOverrides = [this, &defaultColors, &userConfig](const ColorMode colorMode)
+    {
+        const QHash<QString, ColorWidget *> &colorWidgets = (colorMode == ColorMode::Light)
+                ? m_lightColorWidgets : m_darkColorWidgets;
+
+        QJsonObject colors;
+        for (auto it = colorWidgets.cbegin(); it != colorWidgets.cend(); ++it)
+        {
+            const QString &colorID = it.key();
+            const QColor &defaultColor = (colorMode == ColorMode::Light)
+                    ? defaultColors.value(colorID).light : defaultColors.value(colorID).dark;
+            const QColor &color = it.value()->currentColor();
+            if (color != defaultColor)
+                colors.insert(it.key(), color.name());
+        }
+
+        if (!colors.isEmpty())
+            userConfig.insert(((colorMode == ColorMode::Light) ? KEY_COLORS_LIGHT : KEY_COLORS_DARK), colors);
+    };
+
+    addColorOverrides(ColorMode::Light);
+    addColorOverrides(ColorMode::Dark);
+
+    const QByteArray configData = QJsonDocument(userConfig).toJson();
+    const nonstd::expected<void, QString> result = Utils::IO::saveToFile((userConfigPath() / Path(CONFIG_FILE_NAME)), configData);
+    if (!result)
+    {
+        const QString error = tr("Couldn't save UI Theme configuration. Reason: %1").arg(result.error());
+        LogMsg(error, Log::WARNING);
+        return false;
+    }
+
+    return true;
+}
+
+bool UIThemeDialog::storeIcons()
+{
+    bool hasError = false;
+
+    const auto updateIcons = [this, &hasError](const ColorMode colorMode)
+    {
+        const QHash<QString, IconWidget *> &iconWidgets = (colorMode == ColorMode::Light)
+                ? m_lightIconWidgets : m_darkIconWidgets;
+        const Path subdirPath = (colorMode == ColorMode::Light)
+                ? Path(u"icons/light"_qs) : Path(u"icons/dark"_qs);
+
+        for (auto it = iconWidgets.cbegin(); it != iconWidgets.cend(); ++it)
+        {
+            const QString &id = it.key();
+            const Path &path = it.value()->currentPath();
+            if (path == m_defaultThemeSource.getIconPath(id, colorMode))
+                continue;
+
+            const Path &userIconPathBase = userConfigPath() / subdirPath / Path(id);
+
+            if (const Path oldIconPath = userIconPathBase + u".svg"
+                    ; path.exists() && !Utils::Fs::removeFile(oldIconPath))
+            {
+                const QString error = tr("Couldn't remove icon file. File: %1.").arg(oldIconPath.toString());
+                LogMsg(error, Log::WARNING);
+                hasError = true;
+                continue;
+            }
+
+            if (const Path oldIconPath = userIconPathBase + u".png"
+                    ; path.exists() && !Utils::Fs::removeFile(oldIconPath))
+            {
+                const QString error = tr("Couldn't remove icon file. File: %1.").arg(oldIconPath.toString());
+                LogMsg(error, Log::WARNING);
+                hasError = true;
+                continue;
+            }
+
+            if (const Path targetPath = userIconPathBase + path.extension()
+                    ; !Utils::Fs::copyFile(path, targetPath))
+            {
+                const QString error = tr("Couldn't copy icon file. Source: %1. Destination: %2.")
+                        .arg(path.toString(), targetPath.toString());
+                LogMsg(error, Log::WARNING);
+                hasError = true;
+            }
+        }
+    };
+
+    updateIcons(ColorMode::Light);
+    updateIcons(ColorMode::Dark);
+
+    return !hasError;
+}
diff --git a/src/gui/uithemedialog.h b/src/gui/uithemedialog.h
new file mode 100644
index 000000000..b1cd1b385
--- /dev/null
+++ b/src/gui/uithemedialog.h
@@ -0,0 +1,69 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2023  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#pragma once
+
+#include <QDialog>
+#include <QHash>
+#include <QString>
+
+#include "uithemesource.h"
+
+namespace Ui
+{
+    class UIThemeDialog;
+}
+
+class ColorWidget;
+class IconWidget;
+
+class UIThemeDialog final : public QDialog
+{
+    Q_OBJECT
+    Q_DISABLE_COPY_MOVE(UIThemeDialog)
+
+public:
+    explicit UIThemeDialog(QWidget *parent = nullptr);
+    ~UIThemeDialog() override;
+
+    void accept() override;
+
+private:
+    void loadColors();
+    void loadIcons();
+    bool storeColors();
+    bool storeIcons();
+
+    Ui::UIThemeDialog *m_ui;
+
+    DefaultThemeSource m_defaultThemeSource;
+    QHash<QString, ColorWidget *> m_lightColorWidgets;
+    QHash<QString, ColorWidget *> m_darkColorWidgets;
+    QHash<QString, IconWidget *> m_lightIconWidgets;
+    QHash<QString, IconWidget *> m_darkIconWidgets;
+};
diff --git a/src/gui/uithemedialog.ui b/src/gui/uithemedialog.ui
new file mode 100644
index 000000000..00247614b
--- /dev/null
+++ b/src/gui/uithemedialog.ui
@@ -0,0 +1,286 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>UIThemeDialog</class>
+ <widget class="QDialog" name="UIThemeDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>451</width>
+    <height>348</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>UI Theme Configuration</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QTabWidget" name="tabWidget">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Expanding" vsizetype="Preferred">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="currentIndex">
+      <number>0</number>
+     </property>
+     <property name="tabBarAutoHide">
+      <bool>true</bool>
+     </property>
+     <widget class="QWidget" name="colorsTab">
+      <attribute name="title">
+       <string>Colors</string>
+      </attribute>
+      <layout class="QVBoxLayout" name="verticalLayout_2">
+       <property name="leftMargin">
+        <number>0</number>
+       </property>
+       <property name="topMargin">
+        <number>0</number>
+       </property>
+       <property name="rightMargin">
+        <number>0</number>
+       </property>
+       <property name="bottomMargin">
+        <number>0</number>
+       </property>
+       <item>
+        <widget class="QScrollArea" name="colorsScrollArea">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Expanding" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="frameShape">
+          <enum>QFrame::NoFrame</enum>
+         </property>
+         <property name="sizeAdjustPolicy">
+          <enum>QAbstractScrollArea::AdjustToContentsOnFirstShow</enum>
+         </property>
+         <property name="widgetResizable">
+          <bool>true</bool>
+         </property>
+         <widget class="QWidget" name="scrollAreaWidgetContents">
+          <property name="geometry">
+           <rect>
+            <x>0</x>
+            <y>0</y>
+            <width>427</width>
+            <height>271</height>
+           </rect>
+          </property>
+          <layout class="QVBoxLayout" name="verticalLayout_3">
+           <item>
+            <layout class="QGridLayout" name="colorsLayout" columnstretch="1,0,0,0,0" columnminimumwidth="0,15,0,15,0">
+             <item row="0" column="0">
+              <widget class="QLabel" name="colorIDLabel">
+               <property name="font">
+                <font>
+                 <bold>true</bold>
+                </font>
+               </property>
+               <property name="text">
+                <string>Color ID</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="2">
+              <widget class="QLabel" name="lightModeColorLabel">
+               <property name="font">
+                <font>
+                 <bold>true</bold>
+                </font>
+               </property>
+               <property name="text">
+                <string>Light Mode</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="4">
+              <widget class="QLabel" name="darkModeColorLabel">
+               <property name="font">
+                <font>
+                 <bold>true</bold>
+                </font>
+               </property>
+               <property name="text">
+                <string>Dark Mode</string>
+               </property>
+              </widget>
+             </item>
+            </layout>
+           </item>
+           <item>
+            <spacer name="colorsSpacer">
+             <property name="orientation">
+              <enum>Qt::Vertical</enum>
+             </property>
+             <property name="sizeHint" stdset="0">
+              <size>
+               <width>20</width>
+               <height>203</height>
+              </size>
+             </property>
+            </spacer>
+           </item>
+          </layout>
+         </widget>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+     <widget class="QWidget" name="iconsTab">
+      <attribute name="title">
+       <string>Icons</string>
+      </attribute>
+      <layout class="QVBoxLayout" name="verticalLayout_5">
+       <property name="leftMargin">
+        <number>0</number>
+       </property>
+       <property name="topMargin">
+        <number>0</number>
+       </property>
+       <property name="rightMargin">
+        <number>0</number>
+       </property>
+       <property name="bottomMargin">
+        <number>0</number>
+       </property>
+       <item>
+        <widget class="QScrollArea" name="iconsScrollArea">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Expanding" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="frameShape">
+          <enum>QFrame::NoFrame</enum>
+         </property>
+         <property name="sizeAdjustPolicy">
+          <enum>QAbstractScrollArea::AdjustToContentsOnFirstShow</enum>
+         </property>
+         <property name="widgetResizable">
+          <bool>true</bool>
+         </property>
+         <widget class="QWidget" name="scrollAreaWidgetContents_2">
+          <property name="geometry">
+           <rect>
+            <x>0</x>
+            <y>0</y>
+            <width>427</width>
+            <height>271</height>
+           </rect>
+          </property>
+          <layout class="QVBoxLayout" name="verticalLayout_4">
+           <item>
+            <layout class="QGridLayout" name="iconsLayout" columnstretch="1,0,0,0,0" columnminimumwidth="0,15,0,15,0">
+             <item row="0" column="0">
+              <widget class="QLabel" name="iconIDLabel">
+               <property name="font">
+                <font>
+                 <bold>true</bold>
+                </font>
+               </property>
+               <property name="text">
+                <string>Icon ID</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="2">
+              <widget class="QLabel" name="lightModeIconLabel">
+               <property name="font">
+                <font>
+                 <bold>true</bold>
+                </font>
+               </property>
+               <property name="text">
+                <string>Light Mode</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="4">
+              <widget class="QLabel" name="darkModeIconLabel">
+               <property name="font">
+                <font>
+                 <bold>true</bold>
+                </font>
+               </property>
+               <property name="text">
+                <string>Dark Mode</string>
+               </property>
+              </widget>
+             </item>
+            </layout>
+           </item>
+           <item>
+            <spacer name="iconsSpacer">
+             <property name="orientation">
+              <enum>Qt::Vertical</enum>
+             </property>
+             <property name="sizeHint" stdset="0">
+              <size>
+               <width>20</width>
+               <height>203</height>
+              </size>
+             </property>
+            </spacer>
+           </item>
+          </layout>
+         </widget>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>UIThemeDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>UIThemeDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/src/gui/uithememanager.cpp b/src/gui/uithememanager.cpp
index 77a237811..2bceb9ef2 100644
--- a/src/gui/uithememanager.cpp
+++ b/src/gui/uithememanager.cpp
@@ -30,370 +30,24 @@
 
 #include "uithememanager.h"
 
-#include <QApplication>
-#include <QDir>
-#include <QFile>
-#include <QJsonDocument>
-#include <QJsonObject>
 #include <QPalette>
 #include <QPixmapCache>
 #include <QResource>
 
-#include "base/algorithm.h"
 #include "base/global.h"
 #include "base/logger.h"
 #include "base/path.h"
 #include "base/preferences.h"
-#include "base/profile.h"
-#include "base/utils/fs.h"
-#include "color.h"
+#include "uithemecommon.h"
 
 namespace
 {
-    const QString CONFIG_FILE_NAME = u"config.json"_qs;
-    const QString STYLESHEET_FILE_NAME = u"stylesheet.qss"_qs;
-
     bool isDarkTheme()
     {
         const QPalette palette = qApp->palette();
         const QColor &color = palette.color(QPalette::Active, QPalette::Base);
         return (color.lightness() < 127);
     }
-
-    QByteArray readFile(const Path &filePath)
-    {
-        QFile file {filePath.data()};
-        if (!file.exists())
-            return {};
-
-        if (file.open(QIODevice::ReadOnly | QIODevice::Text))
-            return file.readAll();
-
-        LogMsg(UIThemeManager::tr("UITheme - Failed to open \"%1\". Reason: %2")
-               .arg(filePath.filename(), file.errorString())
-               , Log::WARNING);
-        return {};
-    }
-
-    QJsonObject parseThemeConfig(const QByteArray &data)
-    {
-        if (data.isEmpty())
-            return {};
-
-        QJsonParseError jsonError;
-        const QJsonDocument configJsonDoc = QJsonDocument::fromJson(data, &jsonError);
-        if (jsonError.error != QJsonParseError::NoError)
-        {
-            LogMsg(UIThemeManager::tr("Couldn't parse UI Theme configuration file. Reason: %1")
-                   .arg(jsonError.errorString()), Log::WARNING);
-            return {};
-        }
-
-        if (!configJsonDoc.isObject())
-        {
-            LogMsg(UIThemeManager::tr("UI Theme configuration file has invalid format. Reason: %1")
-                   .arg(UIThemeManager::tr("Root JSON value is not an object")), Log::WARNING);
-            return {};
-        }
-
-        return configJsonDoc.object();
-    }
-
-    QHash<QString, QColor> colorsFromJSON(const QJsonObject &jsonObj)
-    {
-        QHash<QString, QColor> colors;
-        for (auto colorNode = jsonObj.constBegin(); colorNode != jsonObj.constEnd(); ++colorNode)
-        {
-            const QColor color {colorNode.value().toString()};
-            if (!color.isValid())
-            {
-                LogMsg(UIThemeManager::tr("Invalid color for ID \"%1\" is provided by theme")
-                       .arg(colorNode.key()), Log::WARNING);
-                continue;
-            }
-
-            colors.insert(colorNode.key(), color);
-        }
-
-        return colors;
-    }
-
-    Path findIcon(const QString &iconId, const Path &dir)
-    {
-        const Path pathSvg = dir / Path(iconId + u".svg");
-        if (pathSvg.exists())
-            return pathSvg;
-
-        const Path pathPng = dir / Path(iconId + u".png");
-        if (pathPng.exists())
-            return pathPng;
-
-        return {};
-    }
-
-    class DefaultThemeSource final : public UIThemeSource
-    {
-    public:
-        DefaultThemeSource()
-        {
-            loadColors();
-        }
-
-        QByteArray readStyleSheet() override
-        {
-            return {};
-        }
-
-        QColor getColor(const QString &colorId, const ColorMode colorMode) const override
-        {
-            if (colorMode == ColorMode::Dark)
-            {
-                if (const QColor color = m_darkModeColors.value(colorId)
-                        ; color.isValid())
-                {
-                    return color;
-                }
-            }
-
-            return m_colors.value(colorId);
-        }
-
-        Path getIconPath(const QString &iconId, const ColorMode colorMode) const override
-        {
-            const Path iconsPath {u"icons"_qs};
-            const Path darkModeIconsPath = iconsPath / Path(u"dark"_qs);
-
-            if (colorMode == ColorMode::Dark)
-            {
-                if (const Path iconPath = findIcon(iconId, (m_userPath / darkModeIconsPath))
-                        ; !iconPath.isEmpty())
-                {
-                    return iconPath;
-                }
-
-                if (const Path iconPath = findIcon(iconId, (m_defaultPath / darkModeIconsPath))
-                        ; !iconPath.isEmpty())
-                {
-                    return iconPath;
-                }
-            }
-
-            if (const Path iconPath = findIcon(iconId, (m_userPath / iconsPath))
-                    ; !iconPath.isEmpty())
-            {
-                return iconPath;
-            }
-
-            return findIcon(iconId, (m_defaultPath / iconsPath));
-        }
-
-    private:
-        void loadColors()
-        {
-            m_colors = {
-                {u"Log.TimeStamp"_qs, Color::Primer::Light::fgSubtle},
-                {u"Log.Normal"_qs, QApplication::palette().color(QPalette::Active, QPalette::WindowText)},
-                {u"Log.Info"_qs, Color::Primer::Light::accentFg},
-                {u"Log.Warning"_qs, Color::Primer::Light::severeFg},
-                {u"Log.Critical"_qs, Color::Primer::Light::dangerFg},
-                {u"Log.BannedPeer"_qs, Color::Primer::Light::dangerFg},
-
-                {u"RSS.ReadArticle"_qs, QApplication::palette().color(QPalette::Inactive, QPalette::WindowText)},
-                {u"RSS.UnreadArticle"_qs, QApplication::palette().color(QPalette::Active, QPalette::Link)},
-
-                {u"TransferList.Downloading"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.StalledDownloading"_qs, Color::Primer::Light::successEmphasis},
-                {u"TransferList.DownloadingMetadata"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.ForcedDownloadingMetadata"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.ForcedDownloading"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.Uploading"_qs, Color::Primer::Light::accentFg},
-                {u"TransferList.StalledUploading"_qs, Color::Primer::Light::accentEmphasis},
-                {u"TransferList.ForcedUploading"_qs, Color::Primer::Light::accentFg},
-                {u"TransferList.QueuedDownloading"_qs, Color::Primer::Light::scaleYellow6},
-                {u"TransferList.QueuedUploading"_qs, Color::Primer::Light::scaleYellow6},
-                {u"TransferList.CheckingDownloading"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.CheckingUploading"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.CheckingResumeData"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.PausedDownloading"_qs, Color::Primer::Light::fgMuted},
-                {u"TransferList.PausedUploading"_qs, Color::Primer::Light::doneFg},
-                {u"TransferList.Moving"_qs, Color::Primer::Light::successFg},
-                {u"TransferList.MissingFiles"_qs, Color::Primer::Light::dangerFg},
-                {u"TransferList.Error"_qs, Color::Primer::Light::dangerFg}
-            };
-
-            m_darkModeColors = {
-                {u"Log.TimeStamp"_qs, Color::Primer::Dark::fgSubtle},
-                {u"Log.Normal"_qs, QApplication::palette().color(QPalette::Active, QPalette::WindowText)},
-                {u"Log.Info"_qs, Color::Primer::Dark::accentFg},
-                {u"Log.Warning"_qs, Color::Primer::Dark::severeFg},
-                {u"Log.Critical"_qs, Color::Primer::Dark::dangerFg},
-                {u"Log.BannedPeer"_qs, Color::Primer::Dark::dangerFg},
-
-                {u"RSS.ReadArticle"_qs, QApplication::palette().color(QPalette::Inactive, QPalette::WindowText)},
-                {u"RSS.UnreadArticle"_qs, QApplication::palette().color(QPalette::Active, QPalette::Link)},
-
-                {u"TransferList.Downloading"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.StalledDownloading"_qs, Color::Primer::Dark::successEmphasis},
-                {u"TransferList.DownloadingMetadata"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.ForcedDownloadingMetadata"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.ForcedDownloading"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.Uploading"_qs, Color::Primer::Dark::accentFg},
-                {u"TransferList.StalledUploading"_qs, Color::Primer::Dark::accentEmphasis},
-                {u"TransferList.ForcedUploading"_qs, Color::Primer::Dark::accentFg},
-                {u"TransferList.QueuedDownloading"_qs, Color::Primer::Dark::scaleYellow6},
-                {u"TransferList.QueuedUploading"_qs, Color::Primer::Dark::scaleYellow6},
-                {u"TransferList.CheckingDownloading"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.CheckingUploading"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.CheckingResumeData"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.PausedDownloading"_qs, Color::Primer::Dark::fgMuted},
-                {u"TransferList.PausedUploading"_qs, Color::Primer::Dark::doneFg},
-                {u"TransferList.Moving"_qs, Color::Primer::Dark::successFg},
-                {u"TransferList.MissingFiles"_qs, Color::Primer::Dark::dangerFg},
-                {u"TransferList.Error"_qs, Color::Primer::Dark::dangerFg}
-            };
-
-            const QByteArray configData = readFile(m_userPath / Path(CONFIG_FILE_NAME));
-            if (configData.isEmpty())
-                return;
-
-            const QJsonObject config = parseThemeConfig(configData);
-
-            auto colorOverrides = colorsFromJSON(config.value(u"colors").toObject());
-            // Overriding Palette colors is not allowed in the default theme
-            Algorithm::removeIf(colorOverrides, [](const QString &colorId, [[maybe_unused]] const QColor &color)
-            {
-                return colorId.startsWith(u"Palette.");
-            });
-            m_colors.insert(colorOverrides);
-
-            auto darkModeColorOverrides = colorsFromJSON(config.value(u"colors.dark").toObject());
-            // Overriding Palette colors is not allowed in the default theme
-            Algorithm::removeIf(darkModeColorOverrides, [](const QString &colorId, [[maybe_unused]] const QColor &color)
-            {
-                return colorId.startsWith(u"Palette.");
-            });
-            m_darkModeColors.insert(darkModeColorOverrides);
-        }
-
-        const Path m_defaultPath {u":"_qs};
-        const Path m_userPath = specialFolderLocation(SpecialFolder::Config) / Path(u"themes/default"_qs);
-        QHash<QString, QColor> m_colors;
-        QHash<QString, QColor> m_darkModeColors;
-    };
-
-    class CustomThemeSource : public UIThemeSource
-    {
-    public:
-        QColor getColor(const QString &colorId, const ColorMode colorMode) const override
-        {
-            if (colorMode == ColorMode::Dark)
-            {
-                if (const QColor color = m_darkModeColors.value(colorId)
-                        ; color.isValid())
-                {
-                    return color;
-                }
-            }
-
-            if (const QColor color = m_colors.value(colorId)
-                    ; color.isValid())
-            {
-                return color;
-            }
-
-            return defaultThemeSource()->getColor(colorId, colorMode);
-        }
-
-        Path getIconPath(const QString &iconId, const ColorMode colorMode) const override
-        {
-            const Path iconsPath {u"icons"_qs};
-            const Path darkModeIconsPath = iconsPath / Path(u"dark"_qs);
-
-            if (colorMode == ColorMode::Dark)
-            {
-                if (const Path iconPath = findIcon(iconId, (themeRootPath() / darkModeIconsPath))
-                        ; !iconPath.isEmpty())
-                {
-                    return iconPath;
-                }
-            }
-
-            if (const Path iconPath = findIcon(iconId, (themeRootPath() / iconsPath))
-                    ; !iconPath.isEmpty())
-            {
-                return iconPath;
-            }
-
-            return defaultThemeSource()->getIconPath(iconId, colorMode);
-        }
-
-        QByteArray readStyleSheet() override
-        {
-            return readFile(themeRootPath() / Path(STYLESHEET_FILE_NAME));
-        }
-
-    protected:
-        virtual Path themeRootPath() const = 0;
-
-        DefaultThemeSource *defaultThemeSource() const
-        {
-            return m_defaultThemeSource.get();
-        }
-
-    private:
-        void loadColors()
-        {
-            const QByteArray configData = readFile(themeRootPath() / Path(CONFIG_FILE_NAME));
-            if (configData.isEmpty())
-                return;
-
-            const QJsonObject config = parseThemeConfig(configData);
-
-            m_colors.insert(colorsFromJSON(config.value(u"colors").toObject()));
-            m_darkModeColors.insert(colorsFromJSON(config.value(u"colors.dark").toObject()));
-        }
-
-        const std::unique_ptr<DefaultThemeSource> m_defaultThemeSource = std::make_unique<DefaultThemeSource>();
-        QHash<QString, QColor> m_colors;
-        QHash<QString, QColor> m_darkModeColors;
-    };
-
-    class QRCThemeSource final : public CustomThemeSource
-    {
-    private:
-        Path themeRootPath() const override
-        {
-            return Path(u":/uitheme"_qs);
-        }
-    };
-
-    class FolderThemeSource : public CustomThemeSource
-    {
-    public:
-        explicit FolderThemeSource(const Path &folderPath)
-            : m_folder {folderPath}
-        {
-        }
-
-        QByteArray readStyleSheet() override
-        {
-            // Directory used by stylesheet to reference internal resources
-            // for example `icon: url(:/uitheme/file.svg)` will be expected to
-            // point to a file `file.svg` in root directory of CONFIG_FILE_NAME
-            const QString stylesheetResourcesDir = u":/uitheme"_qs;
-
-            QByteArray styleSheetData = CustomThemeSource::readStyleSheet();
-            return styleSheetData.replace(stylesheetResourcesDir.toUtf8(), themeRootPath().data().toUtf8());
-        }
-
-    private:
-        Path themeRootPath() const override
-        {
-            return m_folder;
-        }
-
-        const Path m_folder;
-    };
 }
 
 UIThemeManager *UIThemeManager::m_instance = nullptr;
diff --git a/src/gui/uithememanager.h b/src/gui/uithememanager.h
index d84d7a55f..3e182769d 100644
--- a/src/gui/uithememanager.h
+++ b/src/gui/uithememanager.h
@@ -39,22 +39,7 @@
 #include <QString>
 
 #include "base/pathfwd.h"
-
-enum class ColorMode
-{
-    Light,
-    Dark
-};
-
-class UIThemeSource
-{
-public:
-    virtual ~UIThemeSource() = default;
-
-    virtual QColor getColor(const QString &colorId, const ColorMode colorMode) const = 0;
-    virtual Path getIconPath(const QString &iconId, const ColorMode colorMode) const = 0;
-    virtual QByteArray readStyleSheet() = 0;
-};
+#include "uithemesource.h"
 
 class UIThemeManager final : public QObject
 {
diff --git a/src/gui/uithemesource.cpp b/src/gui/uithemesource.cpp
new file mode 100644
index 000000000..04b41d3d9
--- /dev/null
+++ b/src/gui/uithemesource.cpp
@@ -0,0 +1,280 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2023  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2019, 2021  Prince Gupta <jagannatharjun11@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If
+ * you modify file(s), you may extend this exception to your version of the
+ * file(s), but you are not obligated to do so. If you do not wish to do so,
+ * delete this exception statement from your version.
+ */
+
+#include "uithemesource.h"
+
+#include <QFile>
+#include <QJsonDocument>
+#include <QJsonObject>
+
+#include "base/global.h"
+#include "base/logger.h"
+#include "base/profile.h"
+
+namespace
+{
+    QByteArray readFile(const Path &filePath)
+    {
+        QFile file {filePath.data()};
+        if (!file.exists())
+            return {};
+
+        if (file.open(QIODevice::ReadOnly | QIODevice::Text))
+            return file.readAll();
+
+        LogMsg(UIThemeSource::tr("UITheme - Failed to open \"%1\". Reason: %2")
+               .arg(filePath.filename(), file.errorString())
+               , Log::WARNING);
+        return {};
+    }
+
+    QJsonObject parseThemeConfig(const QByteArray &data)
+    {
+        if (data.isEmpty())
+            return {};
+
+        QJsonParseError jsonError;
+        const QJsonDocument configJsonDoc = QJsonDocument::fromJson(data, &jsonError);
+        if (jsonError.error != QJsonParseError::NoError)
+        {
+            LogMsg(UIThemeSource::tr("Couldn't parse UI Theme configuration file. Reason: %1")
+                   .arg(jsonError.errorString()), Log::WARNING);
+            return {};
+        }
+
+        if (!configJsonDoc.isObject())
+        {
+            LogMsg(UIThemeSource::tr("UI Theme configuration file has invalid format. Reason: %1")
+                   .arg(UIThemeSource::tr("Root JSON value is not an object")), Log::WARNING);
+            return {};
+        }
+
+        return configJsonDoc.object();
+    }
+
+    QHash<QString, QColor> colorsFromJSON(const QJsonObject &jsonObj)
+    {
+        QHash<QString, QColor> colors;
+        for (auto colorNode = jsonObj.constBegin(); colorNode != jsonObj.constEnd(); ++colorNode)
+        {
+            const QColor color {colorNode.value().toString()};
+            if (!color.isValid())
+            {
+                LogMsg(UIThemeSource::tr("Invalid color for ID \"%1\" is provided by theme")
+                       .arg(colorNode.key()), Log::WARNING);
+                continue;
+            }
+
+            colors.insert(colorNode.key(), color);
+        }
+
+        return colors;
+    }
+
+    Path findIcon(const QString &iconId, const Path &dir)
+    {
+        const Path pathSvg = dir / Path(iconId + u".svg");
+        if (pathSvg.exists())
+            return pathSvg;
+
+        const Path pathPng = dir / Path(iconId + u".png");
+        if (pathPng.exists())
+            return pathPng;
+
+        return {};
+    }
+}
+
+DefaultThemeSource::DefaultThemeSource()
+    : m_defaultPath {u":"_qs}
+    , m_userPath {specialFolderLocation(SpecialFolder::Config) / Path(u"themes/default"_qs)}
+    , m_colors {defaultUIThemeColors()}
+{
+    loadColors();
+}
+
+QByteArray DefaultThemeSource::readStyleSheet()
+{
+    return {};
+}
+
+QColor DefaultThemeSource::getColor(const QString &colorId, const ColorMode colorMode) const
+{
+    return (colorMode == ColorMode::Light)
+            ? m_colors.value(colorId).light : m_colors.value(colorId).dark;
+}
+
+Path DefaultThemeSource::getIconPath(const QString &iconId, const ColorMode colorMode) const
+{
+    const Path iconsPath {u"icons"_qs};
+    const Path lightModeIconsPath = iconsPath / Path(u"light"_qs);
+    const Path darkModeIconsPath = iconsPath / Path(u"dark"_qs);
+
+    if (colorMode == ColorMode::Dark)
+    {
+        if (const Path iconPath = findIcon(iconId, (m_userPath / darkModeIconsPath))
+                ; !iconPath.isEmpty())
+        {
+            return iconPath;
+        }
+
+        if (const Path iconPath = findIcon(iconId, (m_defaultPath / darkModeIconsPath))
+                ; !iconPath.isEmpty())
+        {
+            return iconPath;
+        }
+    }
+    else
+    {
+        if (const Path iconPath = findIcon(iconId, (m_userPath / lightModeIconsPath))
+                ; !iconPath.isEmpty())
+        {
+            return iconPath;
+        }
+    }
+
+    return findIcon(iconId, (m_defaultPath / iconsPath));
+}
+
+void DefaultThemeSource::loadColors()
+{
+    const QByteArray configData = readFile(m_userPath / Path(CONFIG_FILE_NAME));
+    if (configData.isEmpty())
+        return;
+
+    const QJsonObject config = parseThemeConfig(configData);
+
+    QHash<QString, QColor> lightModeColorOverrides = colorsFromJSON(config.value(KEY_COLORS_LIGHT).toObject());
+    for (auto overridesIt = lightModeColorOverrides.cbegin(); overridesIt != lightModeColorOverrides.cend(); ++overridesIt)
+    {
+        auto it = m_colors.find(overridesIt.key());
+        if (it != m_colors.end())
+            it.value().light = overridesIt.value();
+    }
+
+    QHash<QString, QColor> darkModeColorOverrides = colorsFromJSON(config.value(KEY_COLORS_DARK).toObject());
+    for (auto overridesIt = darkModeColorOverrides.cbegin(); overridesIt != darkModeColorOverrides.cend(); ++overridesIt)
+    {
+        auto it = m_colors.find(overridesIt.key());
+        if (it != m_colors.end())
+            it.value().dark = overridesIt.value();
+    }
+}
+
+QColor CustomThemeSource::getColor(const QString &colorId, const ColorMode colorMode) const
+{
+    if (colorMode == ColorMode::Dark)
+    {
+        if (const QColor color = m_darkModeColors.value(colorId)
+                ; color.isValid())
+        {
+            return color;
+        }
+    }
+
+    if (const QColor color = m_colors.value(colorId)
+            ; color.isValid())
+    {
+        return color;
+    }
+
+    return defaultThemeSource()->getColor(colorId, colorMode);
+}
+
+Path CustomThemeSource::getIconPath(const QString &iconId, const ColorMode colorMode) const
+{
+    const Path iconsPath {u"icons"_qs};
+    const Path darkModeIconsPath = iconsPath / Path(u"dark"_qs);
+
+    if (colorMode == ColorMode::Dark)
+    {
+        if (const Path iconPath = findIcon(iconId, (themeRootPath() / darkModeIconsPath))
+                ; !iconPath.isEmpty())
+        {
+            return iconPath;
+        }
+    }
+
+    if (const Path iconPath = findIcon(iconId, (themeRootPath() / iconsPath))
+            ; !iconPath.isEmpty())
+    {
+        return iconPath;
+    }
+
+    return defaultThemeSource()->getIconPath(iconId, colorMode);
+}
+
+QByteArray CustomThemeSource::readStyleSheet()
+{
+    return readFile(themeRootPath() / Path(STYLESHEET_FILE_NAME));
+}
+
+DefaultThemeSource *CustomThemeSource::defaultThemeSource() const
+{
+    return m_defaultThemeSource.get();
+}
+
+void CustomThemeSource::loadColors()
+{
+    const QByteArray configData = readFile(themeRootPath() / Path(CONFIG_FILE_NAME));
+    if (configData.isEmpty())
+        return;
+
+    const QJsonObject config = parseThemeConfig(configData);
+
+    m_colors.insert(colorsFromJSON(config.value(KEY_COLORS).toObject()));
+    m_darkModeColors.insert(colorsFromJSON(config.value(KEY_COLORS_DARK).toObject()));
+}
+
+Path QRCThemeSource::themeRootPath() const
+{
+    return Path(u":/uitheme"_qs);
+}
+
+FolderThemeSource::FolderThemeSource(const Path &folderPath)
+    : m_folder {folderPath}
+{
+}
+
+QByteArray FolderThemeSource::readStyleSheet()
+{
+    // Directory used by stylesheet to reference internal resources
+    // for example `icon: url(:/uitheme/file.svg)` will be expected to
+    // point to a file `file.svg` in root directory of CONFIG_FILE_NAME
+    const QString stylesheetResourcesDir = u":/uitheme"_qs;
+
+    QByteArray styleSheetData = CustomThemeSource::readStyleSheet();
+    return styleSheetData.replace(stylesheetResourcesDir.toUtf8(), themeRootPath().data().toUtf8());
+}
+
+Path FolderThemeSource::themeRootPath() const
+{
+    return m_folder;
+}
diff --git a/src/gui/uithemesource.h b/src/gui/uithemesource.h
new file mode 100644
index 000000000..bfd89546c
--- /dev/null
+++ b/src/gui/uithemesource.h
@@ -0,0 +1,115 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2023  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2019  Prince Gupta <jagannatharjun11@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If
+ * you modify file(s), you may extend this exception to your version of the
+ * file(s), but you are not obligated to do so. If you do not wish to do so,
+ * delete this exception statement from your version.
+ */
+
+#pragma once
+
+#include <memory>
+
+#include <QtGlobal>
+#include <QColor>
+#include <QHash>
+#include <QIcon>
+#include <QString>
+
+#include "base/path.h"
+#include "uithemecommon.h"
+
+enum class ColorMode
+{
+    Light,
+    Dark
+};
+
+class UIThemeSource
+{
+    Q_DECLARE_TR_FUNCTIONS(UIThemeSource)
+
+public:
+    virtual ~UIThemeSource() = default;
+
+    virtual QColor getColor(const QString &colorId, const ColorMode colorMode) const = 0;
+    virtual Path getIconPath(const QString &iconId, const ColorMode colorMode) const = 0;
+    virtual QByteArray readStyleSheet() = 0;
+};
+
+class DefaultThemeSource final : public UIThemeSource
+{
+public:
+    DefaultThemeSource();
+
+    QByteArray readStyleSheet() override;
+    QColor getColor(const QString &colorId, const ColorMode colorMode) const override;
+    Path getIconPath(const QString &iconId, const ColorMode colorMode) const override;
+
+private:
+    void loadColors();
+
+    const Path m_defaultPath;
+    const Path m_userPath;
+    QHash<QString, UIThemeColor> m_colors;
+};
+
+class CustomThemeSource : public UIThemeSource
+{
+public:
+    QColor getColor(const QString &colorId, const ColorMode colorMode) const override;
+    Path getIconPath(const QString &iconId, const ColorMode colorMode) const override;
+    QByteArray readStyleSheet() override;
+
+protected:
+    virtual Path themeRootPath() const = 0;
+    DefaultThemeSource *defaultThemeSource() const;
+
+private:
+    void loadColors();
+
+    const std::unique_ptr<DefaultThemeSource> m_defaultThemeSource = std::make_unique<DefaultThemeSource>();
+    QHash<QString, QColor> m_colors;
+    QHash<QString, QColor> m_darkModeColors;
+};
+
+class QRCThemeSource final : public CustomThemeSource
+{
+private:
+    Path themeRootPath() const override;
+};
+
+class FolderThemeSource : public CustomThemeSource
+{
+public:
+    explicit FolderThemeSource(const Path &folderPath);
+
+    QByteArray readStyleSheet() override;
+
+private:
+    Path themeRootPath() const override;
+
+    const Path m_folder;
+};