So Im making a cake for my nephews 12th birthday. He loves Legos and is receiving the new Monster Fighters for his big day. Now I have decided to stay in the theme and make the crazy scientists monster (basically Frankenstein) Lego head cake. Now if you know Lego heads they all have a painted face and I have a few questions about painting on green colored fondant. Can I just use the Icing colors (black) to paint the face onto the green fondant? And if I can use Icing colors do I need to do anything special with it first? One more question, there are several spots on his face that are white (his teeth) so how would I do that?
P.S. I have looked everywhere for white icing color in our area and cannot find any and I cannot wait for any to arrive in the mail any ideas or suggestions would help.

You can use black icing color to paint on the face. If you use straight color it will not dry, it will remain tacky. You can mix it with high proof alcohol (everclear or vodka) then paint on. The alcohol dries off & does not leave a taste. Some people are not comfortable with this method on children's cake & prefer to use vanilla extract. You could also use the food coloring markers, depending on how large of an area you are covering.

Would using white fondant cutouts work for the teeth & other white areas? That would probably be the easiest route. My local hobby lobby has the white food coloring. I have used it to paint small areas onto black fondant & it showed up well. But I'm not sure if it would be efficient for larger areas.

Duff and Americolor sell a white coloring. Wilton has white in a much larger bottle called Icing White or something similar.