That's right, rainbow cupcakes.
I didn't make this recipe myself, but I found it HERE and decided to try it out. So, here's their recipe, with my lovely pictures.
To make it easier on yourself, buy cake mix and use that to make the batter. It will make more cupcakes, too.
Recipe I used is italicized; the regular font is things I wanted to add.
Makes 12 Cupcakes