This maybe a stupid question, but can you paint colors onto your buttercream without it running or doing funny things? I would like to do this on a cake but don't want to ruin it. Thanks.
I've never tried it, but these links might give you some ideas:
I made a BC-covered cake last month and experimented with painting on it. I mixed a little black gel color with a teaspoon or two of vodka. I painted Japanese lettering and cherry tree branches on top of the crusted BC and it worked just fine- no running, melting, or bleeding. Just make sure it's not too "wet" by testing on a paper towel. Too much bleeding on the towel will tell you if you need less liquid or more gel color. And, make sure you're using paintbrushes that you have designated only for food use.