Library.ColorChooser.CreateWidget(frame, handler, pixel, colorsafe, saturation)
The widget will be placed at the top-left corner of the user provided frame.
The 'handler' is called, passing red, green, and blue as return values.
Use 'pixel' to control how large each color block is. Default is 5 pixels.
Use 'colorsafe' to indicate whether to offer colorsafe colors only or not.
Use 'saturation' to adjust the saturation.