Preheat oven to 325
Spray bundt pan and set aside.
Make white cake mix as directed on the box.
Separate the batter into four bowls (or three if you only want three colors) of one cup each.
Color one orange, one green, one black, one purple.
Pour one color of batter into the bottom of the bundt pan at a time. They will naturally layer on top of one another. Do not mix the batter.
Bake as directed on the box, usually about 20-25 minutes. Once the cake is done, let cool 5-10 minutes then turn out onto a plate. Let cool completely - about 30 minutes.
Meanwhile, you can make the frosting by dividing the white frosting into thirds. Color 1/3 purple, 1/3 green, and 1/3 orange.
With sweeping motions, drizzle each color over the cake. Overlap colors and have fun with the design! Add sprinkles immediately before the frosting sets. Let the icing set and then serve.