Grease and line 3 9-inch (20 cm) round cake pans with parchment paper.
Set aside 1 bowl of cake batter – this will be the white part of the cake. Add 2 teaspoons of red food coloring to another bowl of batter, mixing until fully incorporated. Add 2 teaspoons of blue food coloring to the last bowl of batter, mixing until fully incorporated.
Take 1 cup (115 G) of each batter and carefully pour into each of the 3 cake pans. Repeat, alternating colors, until all of the batter is used. Gently stir to blend the colors in each pan.
Bake according to package instructions, or until a toothpick inserted in the center of a cake comes out clean.
Line a baking sheet with parchment paper and lay 3 wooden skewers 4 inches (10 cm) apart.
In a small heat-proof bowl, melt the red hard candies in the microwave for 1 minute. Using a small spoon, carefully drizzle the red candy in a star pattern over the skewers. Cool for 5 minutes.
In another small glass bowl, melt the blue hard candies in the microwave for 1 minute. Using a small spoon, carefully drizzle the blue candy in a star pattern over the red candy. Cool for 10 minutes before gently prying away from the parchment.
Remove all the cakes from the pans and let cool completely before continuing.
With a serrated knife, removed the domed tops from each cake layer and set aside the excess cake.
Place a dab of frosting on a cake stand or an inverted plate. Place a layer of cake on the cake wheel, then evenly spread frosting on top. Place the next layer of cake on top of the frosted layer, and spread frosting on top. Add the last cake layer.
Add 1 cup (115 G) of frosting on top of the cake, spreading evenly across the top and sides with a spatula.
Dab the blue and red frosting around the sides cake, alternating from top to bottom, about 3 inches (7 cm) apart.
Using a spatula, smear the red and blue frosting onto the sides of the cake.