The Stained Glass Cake

My (oldest) brother is finally admitting that he has a birthday and as that he allowed to do something besides, dig fence posts (which was his original plan for the day), I have made a cake to celebrate. I had some trouble coming up with an idea for this cake, but since it was going to be the first one made in my new place with my new Kitchenaid mix master, I thought it should be something good. I decided to go with a stained glass kind of idea. It didn't turn out exactly how I would have liked, but the colors are vibrant and I think the idea pretty much gets across.
It is a yellow cake with a maple butter cream filling.