I'm making a frog cake, which is new for me. The first fluffy white frosting I found is sort of a meringuey one, with raw eggwhites cooked to 160 degrees. Ordinarily I'd be comfortable with that, but one of my guests has a compromised immune system and I want to be super-careful about egg whites. So I guess I'm looking for a buttercream that will work well with a shape cake with lots of curves, and will take the green and blue food coloring well.
Can anybody offer a good recipe? Can I just do the powdered sugar-butter-vanilla thing and have it be really nice?