Preheat the Oven and Prepare Your Pan - Preheat your oven to 350 degrees Farenheit. Grease your bundt pan with cooking spray.
Prepare your Cake - Using an electric mixer, beat the cake mix, water, vegetable oil, and eggs in a large bowl until combined. Place one cup of batter in a small bowl and add in one teaspoon of red food coloring. In another small bowl, place one cup of batter and add in blue food coloring.
Bake the Cake - Add the red batter, then the white batter, and then the blue batter to the cake pan. Bake for around 40-45 minutes or until a toothpick inserted into the middle comes out clean. Let the cake cool for 10 minutes in the pan before flipping onto the wire rack, with parchment paper underneath.
Decorate the Cake - In three separate bowls, add 1/4 cup of frosting. Microwave the first bowl for 10-15 seconds then use a fork to drizzle it onto the cake. Microwave the second bowl for 10-15 seconds and add red food coloring, then drizzle on the cake.
For the third bowl, microwave for 10-15 seconds and add blue food coloring, then drizzle it on the cake. Add the red, white, and blue sprinkles, then let the cake set for 30 minutes before serving.