The best colourer (is that even a word?) that I know (ok I don't really know her but I stalk her blog) is Debbie Olson!
OH-MY-GOODNESS!!! YOU should check out her latest Copic Tutuorial.
Yes I'm talking to you - you should go there right now - click HERE to see her post.
ahhhhhhh..... I wish I good colour as good as Debbie ....