I need some advice. How do you make buttercream icing into the primary colors like bright red and royal blue and most importantly purple! I have been doing cakes for a couple of years, and I have yet to master coloring the buttercream! With red it always comes out a muddy looking burgandy, with blue, I am usually close, but with purple, it looks more like a shade of blue. Any suggestions other than simply buying it colored, I will welcome!