Pierce the bottoms of each plastic Easter egg with a scissor. Adults should do this part. Make the hole big enough to use the syringe.
Prepare Jell-O flavors, each in separate bowls. Use only 1/2 cup of boiling water per flavor to dissolve the gelatin.
Generously oil the inside of each egg. This will help Jell-O egg removal.
If your plastic eggs have holes on the tops you will need to add 1 teaspoon of oil to each compartment of the egg carton, Place this in the fridge for 5 minutes. This will make it so the Jell-O does not leak out.
Place the eggs, top side down into the egg carton.
Fill a syringe with some Jell-O and start filling the eggs with a thin layer. Place in the fridge for 20 minutes or until the layer is set. Continue this process until the eggs are filled.
You can add a little bit of sour cream or yogurt to the Jell-O as you go to make the color lighter and opaque. Feel free to experiment!
To remove Jell-O eggs from the plastic shell, run them under some warm water. This will help loosed them from the edges.