wow, this is great! I've been trying to find this for a while. Their theory page (http://en.wikipedia.org/wiki/Lab_color_space http://en.wikipedia.org/wiki/Lab

wow, this is great! I've been trying to find this for a while. Their theory page (http://en.wikipedia.org/wiki/Lab_color_space http://en.wikipedia.org/wiki/Lab_color_space) goes into how they do it, it's a pretty interesting approach of pre-calculating using CIE lab and then hcl for display/ui. And the ui is well done, too.