1Heat oven to 350°F. Grease bottom only of 13x9-inch pan with shortening or cooking spray.
2In large bowl, beat cake mix, food color, water, oil and eggs with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Stir in chocolate chips. Pour into pan.
3Bake 32 to 37 minutes or until toothpick inserted in center comes out clean. Cool completely, about 1 hour.
4Frost top of cake with white frosting. Pipe ribbon in desired colors using decorating icing. Store loosely covered at room temperature.