Go Back

Rainbow Cake

Prep Time 1 hour 45 minutes
Cook Time 30 minutes
Total Time 2 hours 15 minutes
Servings 12 servings
Author cindy


  • 2 15.25 oz packages of white cake mix
  • Water vegetable oil and eggs-as called for on the cake mix box
  • Gel food coloring red yellow, blue, green plus orange and purple if you can find it.
  • 3 16 oz cans ready-to-spread vanilla frosting divided
  • 2 3/4 cups powdered sugar divided


The 6 Cakes

  1. Preheat the oven to 350°
  2. Grease six 8" round cake pans, line with parchment paper
  3. Prepare a double batch of cake mix according to package directions, using water, vegetable oil and eggs
  4. Divide the batter evenly between 6 bowls (1 1/3 cups of batter in each bowl)
  5. Stir 1/8 tsp each of blue, green, yellow and purple food coloring into 4 of the batters (you can make purple by combining red and blue)
  6. Stir 1/2-1 tsp of orange food coloring into the 5th bowl (you can combine red and yellow to make orange)
  7. Stir 3/4-1 tsp of red food coloring in the 6th bowl of batter
  8. Pour the batters into the prepared pans
  9. Bake the cake layers at 350° for 13-15 minutes, or until a wooden toothpick inserted in center comes out clean
  10. Cool in pans on wire racks for 10 minutes
  11. Remove cakes from pans to wire racks and cool completely (about 1 hour)

The Frosting

  1. Beat 2 cans frosting with 1 cup powdered sugar at medium speed with an electric mixer until light and fluffy (2-3 minutes)
  2. Stack cake layers with 1/3 cup frosting in between each layer
  3. With 1 1/4 cups frosting, spread a thin layer of frosting on top and sides of cake
  4. Add remaining can of frosting and 1 3/4 cups powdered sugar to remaining frosting in bowl
  5. Beat at medium speed with an electric mixer until light and fluffy (2-3 minutes)
  6. Divide frosting into 3 bowls
  7. Tint 2 bowls different shades of light blue
  8. Frost cake with deepest blue toward the bottom and white frosting on top
  9. Use back of spoon to blend and swirl frosting

Recipe Notes

1. I only had 3 pans so I baked 3 layers at a time and refrigerated the batter that was waiting to be used.
2. I couldn't find all 6 colors of gel food coloring so I mixed colors to make purple and orange.
3. I chose not to follow the directions for the ombre frosting. I decorated with jelly beans instead.