I had not seen this done before so already the idea and when my client said rainbow cake I was so delighted I would get to try this. So the sides are all rainbow sours candy and then the top is sprinkles with a fondant rainbow, cloud and of course you must have a pot of gold to finish it off. The inside was also 6 tiers of rainbow colors starting with purple ending with red. The cake is vanilla with cookies and cream buttercream.