The breeder I got Shelby from was feeding him the fruitblend zupreem. I kept Shelby on it for a while, but I disliked the way it colored his droppings. Droppings tell a lot about birds, and I didn't want the color to compromise my being able to get him to the vet on time if he's sick.
I have been weaning him off of the fruitblend onto the natural, also by Zupreem. He didn't like it at first (he hated the yellow banana pieces, and always left those over and the color of the natural is similar), but he's been eating more and more of the natural every day. Sure the colors look fun, but I myself don't like putting artificial coloring into my body, why give it to my bird? Even if the food does smell like fruit loops.