Add 18 sheets (2 sleeve packages) of graham crackers to a gallon sealable baggie. Zip bag closed tightly and crush crackers to crumbs with a kitchen mallet. Microwave 1/2 c. butter with 2 Tbsp. caramel syrup for about a minute. Stir and pour over graham cracker crumbs. Stir well to coat crumbs. Spray a 9x13 inch glass baking dish with cooking spray. Press cracker mixture evenly across entire bottom of the pan. Place on a flat shelf in the freezer for about 40 minutes.
Heat 1 1/4 cups of water to boiling, mix with 6 ounce packet of blue @Jell-O (berry blue or cotton candy) in a bowl. Stir until dissolved. Set bowl in the fridge for about 5 minutes to cool prior to pouring over cracker crumbs. Refrigerate for 45 minutes to 1 hour.
Pull pan from freezer. Heat 1 1/4 cups of water to boiling, mix with one 6 ounce packet of red Jell-O (cherry, raspberry, or strawberry) in a bowl. Stir well. Set in the fridge for about 5 minutes to cool prior to pouring it over the blue Jell-O. Set in the freezer on flat shelf for about 45 minutes to 1 hour.
Pull pan from freezer. Heat 1 1/4 cups of water to boiling, mix with one 6 ounce packet of blue Jell-O. Stir well. Set in the fridge for about 5 minutes to cool prior to pouring over the red Jell-O layer. Set in the freezer on flat shelf for about 45 minutes to 1 hour. Pull pan from freezer and score entire surface of @Jell-O lightly with a fork. This helps the topping stay on top of the @Jell-O.
To make topping, mix together 1/2 c. marshmallow creme and 1/2 c. Cool Whip. Blend with a hand mixer for 20-30 seconds. Spread topping across Jell-O with a spatula.
Slice into small pieces. Store in the freezer (for a short time) or refrigerator. Don't leave it freezer for too long, don't let it freeze.