diff --git a/src/calibre/gui2/dialogs/palette.py b/src/calibre/gui2/dialogs/palette.py
index e96edac3a1..ce03d35cdd 100644
--- a/src/calibre/gui2/dialogs/palette.py
+++ b/src/calibre/gui2/dialogs/palette.py
@@ -38,7 +38,7 @@ class Color(QWidget):
         l.addWidget(la)
 
     def restore_defaults(self):
-        self.button.color = self.default_palette.color(*self.color_key)
+        self.button.color = self.default_palette.color(*self.color_key).name()
 
     def color_changed(self):
         self.changed.emit()
@@ -178,6 +178,7 @@ class PaletteConfig(Dialog):
         with gprefs:
             self.light_tab.apply_settings()
             self.dark_tab.apply_settings()
+        Application.instance().palette_manager.refresh_palette()
 
     def restore_defaults(self):
         self.light_tab.restore_defaults()
diff --git a/src/calibre/gui2/palette.py b/src/calibre/gui2/palette.py
index db0197d413..05b675c09a 100644
--- a/src/calibre/gui2/palette.py
+++ b/src/calibre/gui2/palette.py
@@ -392,6 +392,12 @@ QTabBar::tab:only-one {
                     self.set_palette(pal)
             self.on_palette_change()
 
+    def refresh_palette(self):
+        is_dark = QApplication.instance().palette().is_dark_theme()
+        pal = dark_palette() if is_dark else light_palette()
+        self.set_palette(pal)
+        self.on_palette_change()
+
     def tree_view_hover_style(self):
         g1, g2 = '#e7effd', '#cbdaf1'
         border_size = '1px'