For my daughters birthday I decided to do a Rainbow cake for her. It was really actually fairly easy. Not as time consuming as I expected. For her cake I made 2- 12'' round pans and 2- 8'' round pans. I used 3 boxes of Duncan Hines Butter recipe yellow cake mix, it was a really moist cake! I highly recommend it. I used 1 box divided between the 2 small rounds and 1 box in each large round pan. Mix the cake mix according to the package and divide the batter into 5-7 bowls. Depending how many colors you want. I used 5 for the small pans and 7 for the large. Pour some food coloring into each bowl. I used blue, orange, green, yellow, red, pink, purple. To make the rainbow design- grease your cake pans and drop spoonfuls of the color you want for the outside in the center of the pan. Go to the next color and drop in the center of the last color. . .repeat. The batter will spread out. For the small cakes I swirled it with a toothpick, but for the large ones I just let it go. Bake as normal.