I found this receipe online , and it was too much fun not to try. It made my little cousin and her step-siblings pretty happy over Easter. You bite inside these rainbow productions and see the hidden color inside. All you need is a white cake mix, neon food coloring, and cupcake trays. Mix the colors in different dishes (I used my room-mate's pottery mugs and bowls because they were the perfect size). Add different spoonfuls of each color into the muffin tins: The finished product: Disguise these in white icing, and let the kids bite inside and count the different colors. They loved it.