ArtStudio has one, you can see it on the screenshot on this page, but you should probably download it to see how it works. I don't really like the program, but this feature is nice :)
Usually I just have a small image open in Photoshop, where I can splash colors around, and pick them quickly.
[edit]Ohh, their site seems to be down, so here's a screen
Perhaps this could be combined with the small color window from Photoshop?
Usually I just have a small image open in Photoshop, where I can splash colors around, and pick them quickly.
[edit]Ohh, their site seems to be down, so here's a screen
Perhaps this could be combined with the small color window from Photoshop?