Yield: 12 servings (5 points per serving for blue, green and purple)
Preheat oven to 325 degrees F. Spray a 9x13 baking dish with no-stick cooking spray.
Add the cake mix and diet 7up to a mixing bowl. Use a hand held mixer on medium for 2 minutes
Stir in the sprinkles then add to the 9x13 pan. Bake 34-38 minutes. When a toothpick inserted in the middle comes out clean the cake is ready. Let it cool.
Add the pudding mix and skim milk to a mixing bowl. Whisk for 2 minutes then fold in the Cool Whip. Spread over the cake. Cut the cake into 12 servings.