Heat oven to 350°F. Spray 60 mini muffin cups with cooking spray. In large bowl, beat cake mix, water, oil and egg whites with electric mixer on low speed 30 seconds. Beat on high speed 2 minutes. Tint batter with pink food color. Divide batter among muffin cups, filling three-fourths full. Bake 10 to 12 minutes or until toothpick inserted in center comes out clean. Cool 5 minutes; remove from pans to cooling racks. Cool completely.