In medium bowl, place frosting; tint with 9 drops yellow and 6 drops red food color to make orange frosting. On plate, place 1 cake, rounded side down. Spread 2/3 cup of the orange frosting over cake almost to edge. Place second cake, rounded side up, on frosted cake to make round shape. Spread a thin layer of frosting over entire cake to seal in crumbs. For easier handling, refrigerate or freeze cake 30 to 60 minutes. Frost entire cake with remaining orange frosting.