DIY Cupcake Frosting Color Chart | via Handmade Charlotte via Food Network [http://www.foodnetwork.com/recipes/articles/frost-by-numbers-how-to-make-frosting-colors.page-2.html] Mix these colors with a standard box of red (r), yellow (y), blue (b) and green (g) food coloring. Mix 1 cup frosting with the drops indicated. (Don't be alarmed: 100 drops is only about 1 tsp.) For homemade frosting, don't add vanilla extract; it will alter the color. For store-bought, use the numbers in parentheses.