Goldfish fry are born a metallic black or gray color. While some remain their original shade for their entire lives, most eventually develop orange or gold color patterns. Poor husbandry can interfere with this process.
Goldfish Development
Baby goldfish are born much darker than they will be as adults. This may be because dark colors helps these small, vulnerable fish escape the attention of predators. With proper husbandry, the fish gradually change color and develop orange or gold scales. Fancy goldfish may develop color patterns including white patches.
Age and Color
Goldfish grow much more slowly than some other fish. Many species are not able to breed until they are 1 year old, and most goldfish are not considered adults until they are about 2 or 3. Fish fry gradually change color over the first year of life, and most fish will be orange or gold by the time they are 1. They may continue getting brighter or darker thereafter, because environmental factors strongly affect goldfish color.
Factors Inhibiting Color
When goldfish get insufficient light, they may turn gray or white. Fish fry that aren't exposed to light may never turn gold. Goldfish should get 12 hours of natural or artificial light daily. Some fungal and bacterial infections may alter a goldfish's color. If you notice growths on your fish's fins, or if your fish stops eating or suddenly changes color, consult a veterinarian or fish expert. Genetics also affect color, and goldfish with dark-colored parents are more likely to have darker colors.
Improving Color
Goldfish are omnivorous scavengers; they will eat anything. While they can survive on fish flakes, flakes don't provide optimal nutrition. Live foods contain protein that can improve fish color. Bloodworm, brine shrimp and mosquito larvae are excellent foods to incorporate into your fish's diet. Feed your fish no more than they can consume in 20 minutes.
