Wtg Poopster!
I've been using the Concentric site... didn't know about the other two. mucho thanks!
Tip on the Concentric website: don't use the CMYK numbers to mix colors... depending on what color profile you have loaded (complicated topic for some other time) you will not get good results. Rather, drag the actual color chips into your paint program and sample them there in RGB.
Poop, what is your opinion of the accuracy of the colors on the other two sites?