I took two white cake mixes and prepared them according to package directions in a huge mixing bowl. Then I separated the batter by putting one and half cups of batter into six smaller bowls (one for every color). Then I mixed in the food coloring - I used the gel kind like this:
Then I took two round cake pans and greased and floured them. Preheated the oven according to the cake package directions. And then the fun began...
I used 2/3 cup of the red batter and put it in the bottom of the first pan, then 1 cup of the orange and 1 cup of the yellow. In the second pan, I put 2/3 cup of the purple batter, then 1 cup of the blue and 1 cup of the green. I dumped the remaining colors in order in the first pan (the rest of the green, blue and purple) and the second pan, I dumped them in reverse order (yellow, orange and red)
It'll look like this in the cake pans:
The author of this recipe explains things better and also uses a weight watchers method by adding soda and omiting the eggs, oil and water. There is also a recipe for WW frosting, but I just used the canned stuff, like I said. You can find the original recipe here. This seriously will become our birthday cake from here on out, if the kids want. Such fun! I've seen people make cupcakes like this too, but I figured that would be to much of a pain in the butt and time consuming, so I just made the cake haha. Happy Baking!!