Add 3 to 5 drops of red gel food coloring to one bowl. Add 3 to 5 drops of blue gel food coloring to the other bowl.
Use a spoon to mix the food coloring into the cake batter. Mix until there are no longer any streaks of food coloring visible.
Transfer the cake batter to piping bags.
Starting with the blue colored cake batter squeeze a small amount into each cupcake liner equally dividing the batter between the cupcake liners.
Repeat with the white and red cake batter.