1. Reason: The gray of black map fish may be caused by insufficient light, and they have sufficient light when they are in their place of origin. If they can't get enough light when they are farmed, their body color will gradually fade.

2. Solution: It is best for breeders to move them to a place where they can receive natural light, so as to ensure that they have enough light. If they can't receive more natural light, the breeder needs to install aquarium lamps to keep their body color.

1. Reason: Black map fish may turn gray because they are cultured in white water for a long time, and they like tender green water. If they are kept in white water for a long time, their body color may fade.

2. Solution: Breeders need to use light green water to breed them, and it is best to install a dark background for them, so as to make them darker and darker.

1. Reason: The gray of black map fish may also be caused by illness. Common colds, enteritis, wound infection, etc. will lead to their dim body color.

2. Solution: Breeders need symptomatic treatment according to their symptoms. After the treatment is cured, their body color will slowly recover. In addition, breeders need to regularly feed them with some color-enhancing feed, which can speed up the recovery of their body color.