We suggest that you tint all icings at one time while cake cools. Refrigerate tinted icing in covered containers until ready to use. Bring to room temperature for decorating.
Make 3 2/3 cups buttercream icing:
Tint 3/4 cup Lemon Yellow/Golden Yellow combination
Tint 1/3 cup black
Tint 1/2 cup red
Tint 1/3 cup gray
Reserve 1 3/4 cups white (thin 1 cup with 2 teaspoons light corn syrup)