Rename the Color singleton to avoid the Qt 6.12 clash

shell/Ui/ToggleSwitch.qml

@@ -40,8 +40,8 @@ Item {
   property bool cursorRing: interactive
   property int cursorPad: Style.space(6)
   property bool rounded: Style.cornerRadius > 0
-  property color foreground: Color.foreground
-  property color accent: Color.accent
+  property color foreground: Colors.foreground
+  property color accent: Colors.accent
 
   signal toggled()
   signal hovered(bool isHovered)