Goldfish will lose their color and turn white if they are kept in the dark and not exposed to any sunlight. – WTF Fun Facts
Source: https://pethelpful.com/fish-aquariums/Why-do-goldfish-change-color
WTF Animal Fact – White Goldfish
Goldfish will lose their color and turn white if they are kept in the dark and not exposed to any sunlight. – WTF Fun Facts
Source: https://pethelpful.com/fish-aquariums/Why-do-goldfish-change-color
No big deal. All animals lose their skin pigmentation making them appear pale or papery white when deprived of sunlight for an extended period.