The color of a goldfish's body is related to the genes in it.

The color of a goldfish's body is related to the genes inside it. The genes determine the type and number of pigment cells inside the goldfish's body. Generally, each goldfish has three types of pigment cells inside its body, which appear as black, orange, and a reflective light blue color.

How many of these cells are present and in what part of the body will determine the color distribution on the goldfish's body surface. Because there are so many possibilities for combinations of pigment cells, this creates color differences between different goldfish. When a goldfish has essentially only one type of pigment cell in its body, it is the monochromatic goldfish you normally see.

Extended information:

The color variations in a goldfish are determined by the amount of melanophores, orange pigmented cells, and light-blue reflective plasmids in the scales of the fish, which are determined by the amount of genetic and environmental conditions control. Goldfish in breeding, the same species in different environments, its color change time is different, color brightness is different.

In order to shorten the color change cycle of goldfish, cultivate colorful and high-quality goldfish, and improve the scientific and technological content of aquaculture, it is necessary to artificially control the four major environmental factors affecting the color change of goldfish.

Baidu Encyclopedia - Goldfish