Start by preheating the oven to 350 degrees. Add the cupcake liners to a cupcake pan.
Add the cake mix to a mixing bowl and mix in the soda, oil, and eggs on medium speed until mixed well.
Add the cupcake batter into the liners about 2/3 full. Bake for 20 minutes or until a toothpick comes out clean. Let the cupcakes cool before frosting.
Cream the butter for about 2 minutes to make the frosting until light and fluffy.
Slowly mix in the powdered sugar 1 cup at a time while adding the half and half or milk a little between each cup. Mix for 1 minute until it is creamy.
Evenly separate the frosting into two mixing bowls. In one bowl, add the lemon jello and yellow food coloring and in the other bowl add the lime jello and green food coloring.
Fill one of the piping bags with the yellow frosting and one with the green.
Put the two small piping bags into a larger piping bag and then squeeze out a bit so that the frosting is flowing.