These are so fun to make! I'm not a kid by any means but I will be making these with my niece who is almost two now. You can use any color you want, I chose neon food coloring because it looks awesome when they are finished. Everyone complemented me on these!
Using white cake mix, make batter as directed. Use several plastic/glass cups, pouring white batter in them, divide between all cups. Add food coloring to each cup for the colors desired. Mix each cup and then put a little of each color in each muffin cup in small blobs. Then drizzle other colors over the blobs. Bake as directed. My kids always wanted these for every birthday and special occasion