to hand paint on fondant? Is it a powdered food coloring and alcohol mixture?
Gel colors diluted with vodka or water, but vodka dries quicker. I use Wilton colors.
You can use alot of things.
Powder color mixed with alcohol
Dusts mixed with alcohol
Gel/Paste colors mixed with alcohol
(or you can mix them with lemon extract)
or Airbrush colors, don't have to be mixed with anything.
I just handpainted a design on a cake a week ago. I tried to mix the gel colors with alcohol, but I must have used too much alcohol, because it just pooled on the surface of the cake. I then tried using the colors straight (I used Americolor gels for this - they are thinner than the Wilton), and it worked well. You just have to be careful not to push too hard with the brush or it will poke holes in the frosting.
ETA: Never mind the last sentence about poking the frosting - I was using buttercream. Wouldn't have that issue with fondant.