A Polka Dot Wedding Cake

Last night I made a polka dot wedding cake. The bride's colors were lavender, eggplant, and champagne. She wanted an unusual flavor for the upper 6" tier: Funfetti! Does anyone know what this is? It's like a white cake with rainbow chips melted into it. I had to test recipes to get the flavor just right - but it needed to be from scratch because box cakes (where you typically find funfetti) are far too light and fluffy for a tiered fondant cake. The lower 9" tier is red velvet.

This is the back side of the cake.