New Post: ColorPicker Idea

If you want the ColorPicker to show a full colored Rectangle (without the white border), you can modify the ColorPicker's template.
In file Xceed.Wof.Toolkit/ColorPicker/Themes/Aero2.NormalColor.xaml (in Windows8)
or Xceed.Wof.Toolkit/ColorPicker/Themes/Generic.xaml (in Windows7)
In the Style of the ColorPicker, make sure the VerticalContentAlignment and HorizontalContentAlignment are "Stretch"
In "PART_ColorPickerToggleButton", there is a Grid, put its margin at "0".