Color Changes in Goldfish

[goldenpuon]

I have heard that goldfish commonly change color after you get them but I don't know what causes it. The goldfish I have now stayed about the same color for the first two years I had them but now they are changing colors pretty dramatically. I once heard that grey was the juvenile coloring for goldfish and that they started to gain their gold coloring after one year yet I saw some young goldfish who were supposedly 3 months old on YouTube who had more mature coloring (they were gold and white.)

A lot of my fish are changing from grey to gold and also some are turning other colors. Salyme used to be a dark grey and is now gold and so is Puon who used to be a light grey. Also, another of my fish named Oranda's orange patch of coloring on her head seems to be dulling to a white.

This is happening over a period of a few months and it brings up a few questions.

What causes goldfish to change color over time?
Are there factors that affect color change in goldfish like maturity, more space, water quality, etc.?
Also, what age do goldfish lose their grey juvenile coloring?

Feedback is appreciated. Thanks.

[Carl]

What causes goldfish to change color over time?

Genetics primarily (including mutations)

Are there factors that affect color change in goldfish like maturity, more space, water quality, etc.?

Diet is the only factor I have demonstrated on tests that can delay or speed up a color change, as well as the 'quality' of the color.

I suspect Water quality including minerals present can be a factor as well, bu I do not have proof.

Also, what age do goldfish lose their grey juvenile coloring?

This can vary greatly, again with genetics, feeding, and possibly water conditions affecting timing

Carl

[goldenpuon]

Thanks for the reply Carl. I have been feeding my goldfish higher quality food in the past year or so than I did the first 2 years I had them. Did the increase in quality of their food likely cause them to change color faster?
I also moved 8 of them to a 40 gallon with more space though my fish in the 2 fish in the 10 gallon are changing color as well. But they still have 5 gallons per fish in each setup.

It would be an great idea for an experiment to conduct to see how nutrition, water quality, and space affect change in coloration. I don't have the space or money to do an experiment like that but I hypothesize that increasing space, quality of food, and keeping good water quality would all speed up the rate the fish changes color as well vibrance of the color.