1 box white cake mix (and ingredients needed to make the cake)
Red food coloring
Blue food coloring
White buttercream frosting
Red, white and blue sprinkles
Preheat oven to 350 degrees. Mix cake according to package instruction. Divide batter in three equal parts (one cup each). Add red food coloring to one and mix. Add blue to the other and mix.
Pour red cake mix into bottom of greased floured bundt pan. Carefully pour white batter on top. Add blue batter on top of white, only covering the middle, not extending to the sides. Do not mix together with a spoon!
Bake as directed (around 30 minutes) and cool for 5 minutes before removing from pan and finishing cooling on a wire rack.
Equally divide frosting in three parts. Mix blue coloring in one, red in another. Microwave white frosting until smooth enough to drizzle on cake, around 5-10 seconds. Use a spoon to drizzle it back and forth around the entire cake.
Repeat process with red and blue, making sure as you drizzle that you can see all colors. Add sprinkles and set aside to dry.