I have only used smbc once for my brothers cake recently nd I wondered itif it did well with colors. I will be makeing a Sweet 15 cake this coming month like one I have posted in my pics. Only with icing and in purple. no fondant. If I did use fondant, like for the accents , would it be ok? Also I know its hot( it has been in the 100's lately her in Kansas!) but the cake will be inside so I hope its ok. I love the taste way better than regular icing, so I hope this will work out!

I use IMBC, but i color cakes like this: I cover the cake in the natural buttercream and then refrigerate it for about 1/2 hour. I then "skim coat" the cake in the colored buttercream. This way there is less color and less chance of the buttercream coloring the guests' mouths.

Thats a good idea, I do that with regular bc icing sometimes. I think I will just airbrush this one though. The accents I will be doing with fondant.

Candy colors or oil-based colors for SMBC. You may end up with streaks if you use gel colors.

Ha! I need to watch this thread because I have such a hard time coloring my SMBC. When I last made it I wanted a spring looking green. Because it was so yellow I had to use a lot of green and in the end it looked like ugly green vomit. My family (test dummies) loved the flavor but did laugh about the color.
I have seen some gorgeous SMBC frosted cakes and I'd love to know how they do it.

Ibeeflower, what type of coloring did you use? As vgcea said, is HAS to be candy/oil-based colors for a good result.

mamapastel, airbrushing won't work on SMBC. The water based color will just bead up on the high fit surface. You can do a teeny bit of shading and maybe some light pearlescence and have ti turn out ok, but not all over color. I know they make special airbrush colors for chocolate, maybe that would work.