This recipe appeared in a story for 50th anniversary of boxed cake mixes. The Color Vision Cake, developed by the Betty Crocker kitchens, uses the fruit gelatin powder of your choice to create a vibrant color and flavor. Recipe from General Mills.

1 (18.25 ounce) package pudding-included white cake mix
3 tablespoons dry gelatin powder from small box fruit-flavored
    gelatin; reserve remaining powder.

Frosting
Reserved gelatin powder
1/3 cup butter or margarine, melted
3 tablespoons evaporated milk, or more as needed
3 1/2 cups confectioners sugar

Preheat oven to 350 degrees F. Grease and flour 2 (8- or 9-inch) round pans, or use cooking spray.

Prepare cake mix as directed on package, except add the 3 tablespoons of dry gelatin with the water. (Reserve remaining gelatin for frosting.) Divide batter between pans. Bake and cool as directed on package.

Meanwhile, beat reserved gelatin, butter and evaporated milk in medium bowl on low speed 1 minute, scraping bowl constantly. Gradually beat in confectioners' sugar until smooth. If necessary, stir in additional evaporated milk, 1/2 teaspoon at a time, until spreadable. Fill layers and frost side and top of cooled cake with frosting.