colorRect="left top right bottom"

This attribute is optional for color pickers that have an image attribute. The colorRect attribute is ignored for other types of items and for color pickers that do not specify an image. If you specify the colorRect attribute, Adobe Dreamweaver displays the color that is currently selected in the color picker in the rectangle, relative to the left or top of the icon. If you do not specify the colorRect attribute, Adobe Dreamweaver does not display the current color on the image.

Example

colorRect="0 12 16 16"