Blackwater Premium Koi & Goldfish Food Color Enhancing Diet is formulated to bring out the maximum vibrancy of color in your Koi, Goldfish, and even Cichlids. Special ingredients aid in bringing out the color needed to enter your fish in competitions or simply make them look their best. For optimum results use for up to 2 months prior to show or competition. This diet contains 4 different natural color enhancers in sufficient quantities to brighten the colors RED and YELLOW. Some color enhancing diets on the market put only enough product in the diet to be listed on the label. We put enough color enhancing ingredients to include over 30% of the diet.