In medium bowl, tint frosting with 9 drops yellow and 6 drops red food color to make orange frosting. Trim bottoms of both cakes to form flat surfaces. Place 1 cake, round side down, on plate. Spread 2/3 cup of the orange frosting over flat side of cake almost to edge. Place second cake, round side up, on frosted cake to make round shape. Frost entire cake with remaining orange frosting.