Rename the Color singleton to avoid the Qt 6.12 clash

shell/Ui/TextField.qml

@@ -18,8 +18,8 @@ import qs.Commons
 TextField {
   id: root
 
-  property color foreground: Color.foreground
-  property color accent: Color.accent
+  property color foreground: Colors.foreground
+  property color accent: Colors.accent
   property color selectionTint: Style.selectionFillFor(foreground, accent)
   property bool password: false
   property real horizontalPadding: Style.spacing.controlPaddingX