We want to use Nopcommerce 3.1 .When we use Color for "Product attributes" in "Control Type" must be one other option (like dropdown, checkbox, color squares....) . User can select a rectangle over the attribute's picture also if picture not available plugin can load any picture and crop a "color squares" with mouse(user can be select with mouse over the picture) on picture. When crop finish it must be save into site image folder. If user open the product details page it must seems like color squares but which we crop over on picture. It must be plugin and we can enable and disable it.
Sample 1 : http://deepliquid.com/projects/Jcr
Sample 2 : http://www.resize.it/crop-a-photo.
Sample 3 : http://odyniec.net/projects/imgare
Sample 4 : http://www.pixelzdesign.com/blog_v