[AppColors] Address review comments

- PaletteEditorDialog::onSave(): compare whole PaletteConfig (colors and
  appColors) so a change to only AccentStrong/AccentSoft writes the file;
  add PaletteConfig::operator==.
- appColor(): derive both roles from QPalette::Highlight unconditionally.
  The Fusion palettes pin Accent to near-Window values, and QPalette::Accent
  only exists on Qt 6.6+, so keying on it made identical themes render very
  differently across Qt versions.
- themeChangedSlot(): merge the theme default's [AppColors] into a custom
  palette that predates the section instead of all-or-nothing per file;
  hasPalette() now counts an appColors-only file as a palette.
- Add Default/palette-default-light.toml so the Default theme's Light scheme
  keeps the classic greens instead of falling back to the OS accent.
- home_widget: restore the isBuiltInTheme() half of the Automatic condition;
  non-built-in themes extract button colors from their own background art.
- palette_grid_widget: use appEnum.value(i) for the role cast (3 sites),
  append appHeader to headerLabels, fix the 'Lighted' typo.

cockatrice/src/interface/palette_editor/palette_editor_dialog.cpp

@@ -297,7 +297,7 @@ void PaletteEditorDialog::onSave()
         if (it.key() == loadedScheme) {
             continue;
         }
-        if (it.value().colors == savedConfig.value(it.key()).colors) {
+        if (it.value() == savedConfig.value(it.key())) {
             continue;
         }
         if (!ThemeManager::commitPalette(saveDir, it.key(), it.value())) {
@@ -308,7 +308,7 @@ void PaletteEditorDialog::onSave()
     }
 
     // Commit the active scheme last so the global colour scheme matches.
-    if (workingConfig[loadedScheme].colors != savedConfig.value(loadedScheme).colors) {
+    if (workingConfig[loadedScheme] != savedConfig.value(loadedScheme)) {
         if (!ThemeManager::commitPalette(saveDir, loadedScheme, workingConfig[loadedScheme])) {
             QMessageBox::warning(this, tr("Save failed"),
                                  tr("Could not write %1 to:\n%2").arg(PaletteConfig::fileName(loadedScheme), saveDir));

cockatrice/src/interface/palette_editor/palette_grid_widget.cpp

@@ -49,7 +49,7 @@ static const QMap<QPalette::ColorRole, const char *> ROLE_DESCRIPTIONS = {
 
 static const QMap<AppColor::Role, const char *> APP_ROLE_DESCRIPTIONS = {
     {AppColor::AccentStrong, QT_TR_NOOP("Vivid primary accent (e.g. home-tab button gradient start)")},
-    {AppColor::AccentSoft, QT_TR_NOOP("Lighted, desaturated accent (e.g. home-tab button gradient end)")},
+    {AppColor::AccentSoft, QT_TR_NOOP("Lightened, desaturated accent (e.g. home-tab button gradient end)")},
 };
 
 PaletteGridWidget::PaletteGridWidget(QWidget *parent) : QWidget(parent)
@@ -144,9 +144,10 @@ void PaletteGridWidget::buildGrid(QWidget *host)
     appHeader->setAutoFillBackground(true);
     appHeader->setContentsMargins(4, 4, 4, 4);
     grid->addWidget(appHeader, appHeaderRow, 0, 1, 4);
+    headerLabels.append(appHeader);
 
     for (int i = 0; i < appEnum.keyCount(); ++i) {
-        auto role = static_cast<AppColor::Role>(i);
+        auto role = static_cast<AppColor::Role>(appEnum.value(i));
         const int row = appHeaderRow + 1 + i;
 
         if (i % 2 == 0) {
@@ -215,7 +216,7 @@ void PaletteGridWidget::loadPalette(const PaletteConfig &cfg)
 
     QMetaEnum appEnum = QMetaEnum::fromType<AppColor::Role>();
     for (int i = 0; i < appEnum.keyCount(); ++i) {
-        auto role = static_cast<AppColor::Role>(i);
+        auto role = static_cast<AppColor::Role>(appEnum.value(i));
         QColor color = cfg.appColors.value(role);
         if (!color.isValid()) {
             color = themeManager->appColor(role);
@@ -235,7 +236,7 @@ PaletteConfig PaletteGridWidget::currentPaletteConfig() const
 
     QMetaEnum appEnum = QMetaEnum::fromType<AppColor::Role>();
     for (int i = 0; i < appEnum.keyCount(); ++i) {
-        auto role = static_cast<AppColor::Role>(i);
+        auto role = static_cast<AppColor::Role>(appEnum.value(i));
         cfg.appColors[role] = appColorButtons[role]->getColor();
     }
 

cockatrice/src/interface/theme_config.cpp

@@ -96,7 +96,7 @@ bool ThemeConfig::save(const QString &themeDirPath) const
 
 bool PaletteConfig::hasPalette() const
 {
-    return !colors.isEmpty();
+    return !colors.isEmpty() || !appColors.isEmpty();
 }
 
 QString PaletteConfig::toToml() const

cockatrice/src/interface/theme_config.h

@@ -39,6 +39,14 @@ struct PaletteConfig
     QMap<QPalette::ColorGroup, QMap<QPalette::ColorRole, QColor>> colors;
     QMap<AppColor::Role, QColor> appColors;
 
+    bool operator==(const PaletteConfig &rhs) const
+    {
+        return colors == rhs.colors && appColors == rhs.appColors;
+    }
+    bool operator!=(const PaletteConfig &rhs) const
+    {
+        return !(*this == rhs);
+    }
     bool hasPalette() const;
     QString toToml() const;
 

cockatrice/src/interface/theme_manager.cpp

@@ -441,14 +441,12 @@ QColor ThemeManager::appColor(AppColor::Role role) const
         return it.value();
     }
 
-    // QPalette::Accent was introduced in Qt 6.6; before that the nearest
-    // accent is the selection highlight, which Accent defaults to when unset.
-    const QColor accent = qApp->palette().color(QPalette::Active,
-#if QT_VERSION >= QT_VERSION_CHECK(6, 6, 0)
-                                                QPalette::Accent);
-#else
-                                                QPalette::Highlight);
-#endif
+    // QPalette::Accent was introduced in Qt 6.6 and several shipped palettes
+    // set it to a value barely distinguishable from Window, so it is not a
+    // reliable accent source. The selection highlight is the stable accent
+    // (Accent defaults to Highlight when unset), and deriving from it
+    // unconditionally keeps every Qt version rendering identically.
+    const QColor accent = qApp->palette().color(QPalette::Active, QPalette::Highlight);
 
     if (role == AppColor::AccentSoft) {
         constexpr int SOFT_SATURATION_PERCENT = 70;
@@ -497,8 +495,19 @@ void ThemeManager::themeChangedSlot()
 
     // ── Load palette: custom first, then theme default ────────────────────
     PaletteConfig palette = PaletteConfig::fromScheme(dirPath, activeScheme);
-    if (!palette.hasPalette()) {
-        palette = ThemeManager::loadDefaultPaletteConfig(dirPath, themeName, activeScheme);
+    const PaletteConfig themeDefault = ThemeManager::loadDefaultPaletteConfig(dirPath, themeName, activeScheme);
+    if (palette.hasPalette()) {
+        // A custom palette written before [AppColors] existed carries no app
+        // colors; merge the theme's shipped defaults so the identity colors
+        // survive (hasPalette() counts an app-colors-only file as a palette,
+        // so those are kept wholesale and never reach here empty).
+        for (auto it = themeDefault.appColors.cbegin(); it != themeDefault.appColors.cend(); ++it) {
+            if (!palette.appColors.contains(it.key())) {
+                palette.appColors.insert(it.key(), it.value());
+            }
+        }
+    } else {
+        palette = themeDefault;
     }
 
     applyStyleAndPalette(themeName, themeCfg, palette, activeScheme);

cockatrice/src/interface/widgets/general/home_widget.cpp

@@ -124,10 +124,13 @@ QPair<QColor, QColor> HomeWidget::determineButtonColor() const
 
     switch (colorSource) {
         case HomeTabButtonColor::Automatic: {
-            if (usesThemeBackground()) {
-                // Static theme background: follow the theme's accent colors.
+            if (usesThemeBackground() && themeManager->isBuiltInTheme()) {
+                // Built-in themes paint a static theme background; follow the
+                // theme's identity accent colors rather than sampling the image.
                 return paletteDerivedButtonColors();
             } else {
+                // Non-built-in themes may ship their own background art, so
+                // extract the button colors from the image actually painted.
                 return extractDominantColors(background);
             }
         }

cockatrice/themes/Default/palette-default-light.toml

@@ -0,0 +1,67 @@
+[Palette]
+WindowText           = #ff000000
+Button               = #fff0f0f0
+Light                = #ffffffff
+Midlight             = #ffe3e3e3
+Dark                 = #ffa0a0a0
+Mid                  = #ffa0a0a0
+Text                 = #ff000000
+BrightText           = #ffffffff
+ButtonText           = #ff000000
+Base                 = #ffffffff
+Window               = #fff0f0f0
+Shadow               = #ff696969
+HighlightedText      = #ffffffff
+Link                 = #ff0d5f28
+LinkVisited          = #ff08401b
+AlternateBase        = #ffe9e7e3
+ToolTipBase          = #ffffffdc
+ToolTipText          = #ff000000
+PlaceholderText      = #80000000
+
+[Palette.Disabled]
+WindowText           = #ff787878
+Button               = #fff0f0f0
+Light                = #ffffffff
+Midlight             = #fff7f7f7
+Dark                 = #ffa0a0a0
+Mid                  = #ffa0a0a0
+Text                 = #ff787878
+BrightText           = #ffffffff
+ButtonText           = #ff787878
+Base                 = #fff0f0f0
+Window               = #fff0f0f0
+Shadow               = #ff000000
+HighlightedText      = #ffffffff
+Link                 = #ff0000ff
+LinkVisited          = #ffff00ff
+AlternateBase        = #fff7f7f7
+ToolTipBase          = #ffffffdc
+ToolTipText          = #ff000000
+PlaceholderText      = #80000000
+
+[Palette.Inactive]
+WindowText           = #ff000000
+Button               = #fff0f0f0
+Light                = #ffffffff
+Midlight             = #ffe3e3e3
+Dark                 = #ffa0a0a0
+Mid                  = #ffa0a0a0
+Text                 = #ff000000
+BrightText           = #ffffffff
+ButtonText           = #ff000000
+Base                 = #ffffffff
+Window               = #fff0f0f0
+Shadow               = #ff696969
+HighlightedText      = #ff000000
+Link                 = #ff0d5f28
+LinkVisited          = #ff08401b
+AlternateBase        = #ffe9e7e3
+ToolTipBase          = #ffffffdc
+ToolTipText          = #ff000000
+PlaceholderText      = #80000000
+
+
+[AppColors]
+AccentStrong        = #ff148c3c
+AccentSoft          = #ff78c850