In a medium saucepan, bring 1 cup of water to a boil. Remove from the heat and whisk in green jello, stirring until dissolved. Add ½ cup cold water and ½ cup vodka, and stir to combine.
Pour the green jello mixture evenly between your 3 oz. cups, filling them about ⅓ full.
Move the cups to the refrigerator to chill for 2 hours.
For the next layer, in a medium saucepan, whisk together 1 cup water and 1 envelope of knox gelatin. Heat to barely a boil. Remove from the heat and pour in sweetened condensed milk and vodka, stir to combine. Allow the mixture to cool completely.
Once the mixture has cooled, add to your jello shot cups, filling ⅔ of the way full, leaving equal room for the last layer. You may have extra of the sweetened condensed milk mixture, which you can discard.
Move the cups back to the refrigerator to chill for another 2 hours.
For the last layer, bring 1 cup of water to a boil. Remove from the heat and whisk in orange jello, until dissolved. Add ½ cup cold water and ½ cup vodka, and stir to combine. Allow the orange jello mixture to cool completely.
Once jello is cool, fill your shot cups the remainder of the way with orange jello.
Move the cups back to the refrigerator to chill for 2 more hours, or until ready to serve.
Before serving, top with whipped cream and orange and green sprinkles.