I had some extra fondant so I figured I'd play around with it. Normally, when coloring fondant you stick it in a food processor and blend it until the color is even all the way through. Since I was testing a decoration though, I used an old paintbrush (this was not for eating!) The idea is nifty, but fondant is thirsty stuff and by the time I got it to the color I wanted, it was starting to fall apart from so much liquid added. Perhaps next time I'll try letting the fondant dry some to develop a crust before "painting" it.