and yes it's hard to believe it's the same fish. Wow what a changer! I finally got my first ochiba this year. She came in 3 months ago at 11 inches and is now 16. I say she because when she came in you couldn't tell body shape wise what it was, now it's obviously a girl! They're a neat koi, don't know how I was able to hold off getting one till now. Let us know if yours keeps changing!
Fortunately for me mine has stayed rock steady the whole time.
To be honest I have watched this color variety, even bred them, and am convinced that when they were created originally the patterns were more stable but as they breed ochiba to ochiba, it seems to create problems. They bruise easier and turn a dark grey and patterns seem easier to be affected.
Where I got mine, Nisei koi farm, Mat breeds his gi-normous female ochiba with male kohakus and there within lies the difference of why I think his are more stable.