As the owner of a goldfish, you may become worried if its color changes gradually and without other signs or symptoms, such as frayed fins or scale loss. It's important to keep this in mind as this change could signal an underlying health issue; thus it's crucial that any signs that accompany such color shift such as frayed fins or scale loss be monitored closely.
Goldfish are extremely hardy creatures, and most instances of their changing color don't indicate any particular illness or disease; however, there may be several potential triggers. A common source is when their tank water quality changes which leads to stress or illness for the fish - this often happens when its pH level goes out of balance (goldfish need an optimal pH range between 6.5-7.5), potentially leading to this form of discoloration over time.
As with flamingoes, goldfish often shift color depending on what they consume; certain foods contain more pigmentation-boosting nutrients than others. To ensure the healthiest diet possible for your goldfish, make sure they include both gel foods as well as high-vitamin supplements (like shrimp krill spirulina algae and spinach) to provide sufficient vitamins. Failing this could result in your goldfish turning white over time.
