How do you keep your Black royal icing from turning your white icing pink? I made a icing plaque for a cake and the black icing turned the white icing next to it pink. Any suggestions? TIA

Ahh, the dreaded bleeding. Your white has to be completely dry. Also helps if your black is pretty stiff. I don't seem to have that trouble with white RBC, don't know if that is an option for you.
Good Luck