private static void OnColorPickerStyleChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
        {
            ColorSelector target   = obj as ColorSelector;
            Style         oldValue = (Style)args.OldValue;
            Style         newValue = (Style)args.NewValue;

            if (oldValue != newValue)
            {
                target.OnColorPickerStyleChanged(oldValue, newValue);
            }
        }
        private static void OnColorChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
        {
            ColorSelector target   = obj as ColorSelector;
            Color         oldValue = (Color)args.OldValue;
            Color         newValue = (Color)args.NewValue;

            if (oldValue != newValue)
            {
                target.OnColorChanged(oldValue, newValue);
            }
        }