Does coloring work on chocolate buttercream frosting? I have a cake order for a pink and purple princess cake and she would like a yellow cake with chocolate frosting. I know that chocolate filling is possible but I wanted to know about coloring chocolate frosting. Any suggestions?

? you could use white chocolate frosting, then color that.

What I would do (or at least give a test run) is make your chocolate buttercream, beat it a little bit longer than normal (the longer you beat it the lighter it will be) to get it a lighter brown color, then try to add your icing colors to see how it works. You could also try some of the wilton icing lightener/whitener paste if you'd like.

I am not too sure it would work very well to get those colors. Do you do fondant? You could ice and fill cake with chocolate and then fondant in your colors on top. That is what I would do.