I have honestly never found foods advertised as "colour enhancing" to do any better than regular foods. Maybe that is just my experience. A variety is best, as unwritten law said. I used to buy one that had four different types in seperate parts in one container, so I could alternate them. I usually have: shrimp pellets, algae wafers, mixed flake and freeze dried bloodworms at all times, then add whatever seems interesting as well. Frozen is good to add as well. Maybe reasearching the basic dietary needs of each fish, then taking a list of those with you will help so you can look at the ingredients on each food?