I have seen shows where they hand paint right onto the cake. I am guessing they just use food coloring/gels and a brush. Can you do this onto BC or does it have to be on fondant?

Does anyone do this often, any thing I should know b4 I try

You can do this on a crusting buttercream. I've never tried it, but I've seen it done.

Not sure either, but I did a test cake recently with colouring gels/pastes on fondant and it looked wonderful. Then I cut it and passed it out to my family. Didnt look so wonderful when their hands were coated in the stuff!!!

what would you do to make white?

Hi sweetmonkey, and welcome to CC!

Thanks for the kind comment on my painted cake. I use gel food colors thinned with vodka, and very soft artist's brushes to paint on well crusted butter-cream. To make white, I use Titanium white color; I have both gel and powder, so I use whichever works best on the particular cake.

I really like this technique, and find it always surprises people to find out that the cake has been painted!

HTH