Using a blender on crush setting, mix 3 cups of ice and grenadine syrup together until slushy. Note: You need this layer to be extra thick, so if needed, add up to 1 cup more ice and blend. When finished, set aside.
Repeat the step for the Blue Curacao, blending with 3 cups of ice until slushy. Like the last layer, you want this to be extra thick. If needed, add up to 1 more cup of ice and blend. Set aside.
Add vodka, lemonade, and remaining 3 cups of ice to the blender and mix until slushy. It’s not as important for this layer to be thick, but it should be comparable to the others. Add up to 1 more cup of ice if needed. When finished, set aside.
Prepare drinks by layering the flavors in this order: grenadine, blue curacao, and finish with the vodka lemonade on top.