Place 24 cups on a large baking sheet. I like to line the baking sheet with parchment paper or paper towels so the cups don't slide around.
Blue Layer
Boil 1 cup of the water and add to a small pitcher or bowl with the blue jello. Stir until dissolved. Add 1 cup of vodka and stir.
Fill your shot containers ⅓ of the way full with the blue jello shot mixture. Allow to cool for 10 minutes. Transfer the sheet pan to the refrigerator and allow the blue layer to set for at least 2 hours.
White Layer
In a small bowl, dissolve the unflavored gelatin in ¼ cup of warm water.
Bring ¾ cups of water to boil. Add the boiling water to the clear gelatin.
Stir in the sweetened condensed milk and vanilla. Add 1 cup of the vodka, stir.
Pour the cream mixture on top of the blue layer until the cups are about ⅔ of the way filled. Transfer the sheet pan to the refrigerator and allow the white layer to set for at least 2 hours.
Red Layer
Boil 1 cup of the water and add to a small pitcher or bowl with the strawberry jello. Stir until dissolved. Add 1 cup of vodka and stir.
Fill your shot containers ⅓ of the way full with the red jello shot mixture. Allow to cool for 10 minutes. Transfer the sheet pan to the refrigerator and allow the final layer to set for at least 2 hours.
Serve as is or decorate with whipped cream, sprinkles, and cherries.
Notes
Freezing the vodka beforehand will ensure the alcohol doesn't evaporate when added to the hot water.
Each layer must be fully set before mixing up and pouring on the next layer.