Thrive’s Nike has a recipe for making rainbow-striped jello Easter Eggs, using Kraft’s “JELL-O JIGGLERS Egg Mold.” She advises coating the mold with generous amounts of cooking spray, then using a syringe to add layers of color, chilling for 10-15 minutes between each layer.
I still remember fondly filling blown eggshells with liquid jello and letting them set in the fridge in an egg-carton, making “hard boiled eggs” that were filled with jello instead.
Rainbow Easter Eggs (via Neatorama)