I like to have in the layered navigation this kind of navigation (see about the colors):
http://www.rei.com/c/womens-shirts?r=c&ir=category%3Awomens-shirts&page=1
What is the easiest way to implement and doing it? We have at the moment all options of colors in one attribute called Color.
How I can do, that I get for example different kind of red in one main color RED.