Preheat oven to 350 degrees F and add cupcake liners to pan.
In a large mixing bowl, beat together the cake mix, egg whites, buttermilk, and oil. Mix on low until it is smooth, turn up mixer to medium and beat for 2 minutes.
Divide batter into 3 bowls, you should have about 1 ¼ cups of batter in each bowl
Color one with red and one with blue food coloring.
Transfer each color of batter to a disposable decorator bag to make it easier to fill cupcakes
Squeeze equal amounts of each color of batter into cupcake liners. ** see tip below
Bake at 350 degrees F for 12-14 minutes or until a toothpick inserted in the center comes out clean.
Cool completely on a wire rack.
Decorate with frosting of your choice, and add sprinkles or other decorations