Combine 1 cup of water and 1 cup of whiskey together in a measuring cup. Place in the refrigerator to chill.
Bring 3/4 cup of water to a boil.
When boiling, measuring out 1/2 cup of the boiling water and add to a small bowl with the orange gelatin powder. Stir until the powder is dissolved.
Add 1 cup of the chilled water whiskey mixture to the orange gelatin. (You will have 1 cup left for the green).
Line up your plastic cups on a baking sheet for easy transport.
Pour the orange gelatin into your plastic cups, approximately 1.5 Tablespoons each.
Chill the orange gelatin until set, approximately 2 hours.
When the orange is set, put two cups of water in the pot with the unflavored gelatin powder. Let the powder soak for a couple minutes.
Heat the water over low until the gelatin is dissolved, about 5 minutes.
Remove from heat and stir in the sweetened condensed milk. Let it cool a little so it is not too hot.
Pour the white gelatin over the orange layer in each cup, approximately 1.5 tablespoons each.
Chill the Jello shots again until the white layer is set, approximately 2 hours.
When the white is set, make the green layer. Heat another 3/4 cup of water and bring to a boil.
Measure out 1/2 cup of the boiling water and add to the green gelatin in a small bowl. Stir to dissolve completely.
Add the remaining 1 cup of the chilled water whiskey mixture to the green.
Let cool slightly until not hot, but not setting.
Pour the green mixture on top of each cup portion, approximately 1.5 Tablespoons per cup.
Chill again until set or ready to serve, at least two hours.