Why have many of the smaller goldfish changed colors while the biggest ones are still mud colored?

Question

I have a large pond (about 10' across about 5' deep at the center) in my backyard. I had two larger goldfish, two smaller ones (the only offspring to survive last years' spawning), and three koi. This spring they had a major orgy and about two months ago I discovered about 100 small dark gray (mud-colored) babies...about 50 left when I counted today (the seagulls love my house). About half a dozen have turned mostly gold (small patches of black on their fins still), one turned white, and about 20 have started showing patches of orange, gold, and/or white color. But I'm confused by one in particular. The ones that have already developed color are about 1.5 to 2" long...most that size have at least some color. Most of the really small ones are still gray, but there are about 10 that are about 3" long (and one big boy that's at nearly 5" long) that show no signs of developing color. Why are there so many sizes and why haven't the largest ones changed color yet?

Answer 1

Genetics. Some will have the domesticated colors and some will have the wild coloration, that's the mud colored ones. Selective breeding has made all these different varieties of goldfish. Many spawn will have natural coloration when cross bred. Unless you are mating two very simular types then you will get this ratio that you have. The wild coloration is dominant gene, colored genes are recessive.

Answer 2

some just dont
thus why fish come in many colors
sarassa/ blue/grey/chocolate etc.
you can try feeding special food for color development plus vitamins
ans see waht happens other wise it will just stay that way

Answer 3

because they are small baby fish they're supose to develope color