You will need:
1 box white cake mix
food coloring in red, blue, yellow, and green
cupcake liners and a cupcake pan
cool whip to top it all off
a few little bowls
Step 1: Make cake batter according to box directions
Step 2: Put equal amounts of cake batter in your small bowl. In each bowl add lots of food coloring. The more food coloring you add the brighter your cupcakes will be. If you don't add enough they will bake up pastel, which would be great for baby showers or easter. To make purple mix red and blue, if you'd like orange mix alot of yellow with a little bit of red. Mix well.
Step 3: Get your oven preheated to 350. Now line your pan with the papers and start layering the batter. I used about a teaspoon of each color. Starting with purple. Just pour each color on top of each other smoothing each color out a little bit before adding the next.
Step 4; Bake according to box directions
Step 5: after they have cooled completely you frost them, cool whip them, decorate to your hearts desire and then enjoy.
All the pics are below.