As parents, we are obsessed with Yo GabbaGabba. It is one kids show that does not make us lose our minds. So we gave the little one a Gabba-themed birthday party and I made a colorful cake.
I'm thrilled with the way it turned out. I bought two boxes of whit cake mix and gel good coloring. I separated prepared batter into 6 equal bowls. I colored each layer to match the characters. I baked each layer in a 9" round pan until a cake tester cake out cleanly - approximately 15 minutes. Let each layer cool individually (also makes much sturdier for lifting. I used a basic buttercream frosting recipe (and it was white enough). Layer each cake in desired color order (I wanted it to look Yo Gabba and not Christmas or rainbow.) Frost in-between. Do a crumb coating of frosting. Chill. (I chilled overnight and finished frosting in the morning. First thing in the morning, I applied the decal. (I think the time helped it meld with the frosting.) There was no "papery" sensation to it.

Having a cake frosting turntable was... awesome! I finished the white frosting layer, filled a bag with yellow frosting and a star tip and slowly covered the sides with stars. I started with logs on top. They were great because I did not have to make a single, perfect ring around the top. Below the long ring, I made a row of stars, turning throughout. The hardest part of the entire cake is recognizing when the frosting has warmed in your hands and is getting less firm. Then it is time to take a 5-10 minute break while the frosting cools in the fridge and your icing hands get a rest. Follow each row of stars to the bottom. You could line the based with logs or beads of frosting, but my stars looked nice.
Refrigerate the cake again until ready to serve. When slicing, We sliced the first two pieces before removing the second one cut, which made for cleaner slices.
Yum!