1. Preheat oven to 350 degrees. Wash and dry the inside of each ball jar. Spray the inside of each jar with nonstick cooking spray. Set jars aside.
2. Prepare cake mix according to box.
3. Scoop about 1 cup of cake batter into five smalls bowls. Add a different color of coloring to each bowl of cake batter until the cake batter is very bright. (The brighter, the better!)
4. Pouring in a circular motion (so colors don't mix together), add 1/4 cup of each color into a each jar (purple on the bottom of each jar, then turquoise, green, yellow and finally pink). Place the jars into a shallow baking dish and add 1/4 inch of water to the bottom of the dish. Place the baking dish in the oven and bake for 35-40 minutes. (test with toothpick...as different ovens and altitudes produce different results)
5. Remove jars and allow to cool completely before scooping out a small portion of the top of your cake (cake will bubble out of the top a bit...so feel free to eat that extra bit right then and there!) and adding a hefty dollop of whipped topping to the top. Finish by topping them off with rainbow colored sprinkles and serve!!!!