First mix any light colored boxed cake mix according to directions.
We used Cherry Chip.
Once divided, (they don't have to be equal), add a different color food coloring to each cup.
I personally suggest using the gel coloring for a more vibrant color but we only had regular so that's what we used.
When they're about 3/4 of the way full, you can use a toothpick to swirl the color a bit, or just leave it alone.
Leave the oven on.
I attempted to add sprinkles, (who doesn't love sprinkles?), but they didn't really stick.