For my daughter's birthday we had a rainbow themed birthday complete with rainbow cake. I don't know why I was so intrigued to make this cake, but at times I wish I had just gone with the chocolate princess cake that my daughter requested at first.
Most of the recipes I saw on pinterest and the like where often from box mixes or this Martha Stewart recipe that did not appeal to me for some reason. I chose to use this vanilla recipe from Smitten Kitchen - I pretty much love all the recipes from the Sky High recipe book and I need to get myself a copy soon. Fairly quickly I decided that I could not stomach using traditional dyes in the cake. I had bought the dyes and just stared at the box thinking that there was no way I could eat something saturated with it. It is one thing to have the frosting be dyed, but the whole cake was too much for me.
I ended up using the natural dyes you can get at Whole Foods and some of them ended up pretty faded (particularly anything that involved red), but once it was all together it didn't seem to make a difference. There were many times during this process that I thought it would be an epic fail, but it turned out good and tasted awesome.