A koi's color cells sit at different depths in the skin, some right near the surface and some deeper in, which ultimately determines how bright the fish appears. The brighter the fish, the bigger ...

You can enhance the colors of your koi fish by providing a proper diet and a well-balanced freshwater aquarium. Unlike most fish species on this list that change color gradually because of age ...

The color of the koi has meaning in Chinese mythology, too. Black koi absorb negativity, according to Novy. Yellow fish are about money and prosperity. The orange and white fish, which are the most ...