i have tried alot of different foods and one of the cheaper foods that i have seen bring out reds is hikari gold/bio gold. i have fed more expensive foods made from better quality ingredients, but for the money, i think hikari gives alot of color for your dollar. i haven't tried gsumo or ching yet. dainichi ultima, color fx, primary krill are all good foods too. look for foods with astaxanthin. it is a natural color enhancer. cyclopeze is supposed to work well too, but i haven't tried this.