I'm actually looking for the same thing as I need to count how many pixels of this and that colors there is in a couple of images.
So anyone knows of this program Dafydd has used, or another one?
Edit: Actualy I found out that Photoshop is able to count that. ^^ it won't list all the colors and numbers, but it will tell you how mane pixles you have marked, so if you only choose one color, tadaa, you've got the answer. and this is how to do it: