Everyone who sees my kitten from the no-kill shelter says he is a non-show-quality Russian Blue - he looks and acts the part, except for having a locket and a white splotch on one foot.
Sure enough, he got green rings around his pupils at around four months, so I’ve been waiting for his eyes to turn fully green. However, he is now around 7 months old and the green does not seem to be progressing much.
It doesn’t matter, of course, but I am curious how the green usually progresses. When would a true Russian Blue cat be expected to have fully green eyes?
I don’t have the answer to your question, but I would like to enforce the law of “cat tax” 
That last part is probably a very solid clue that he is in fact mixed breed. Piebald spotting is a dominant trait and unlikely to have been lurking in any pure-bred Russian Blue. So I’d guess at one Russian Blue parent and one…not :). Or at least partially not.
Poking about quickly all I’m finding is that full green eyes are “adult”, but it is worth remembering that for show cats anything over 8 months is considered adult. So it might happen soonish or it is entirely possible his eyes might just freeze that way. For awhile anyway.
But cat eye color is occasionally an oddly variable thing. Older cats will often tend to deposit dark melanin spots in the eyes over times, so that they look a little “dirty”( it is one way to sometimes guess you’re dealing with a geriatric cat ), but eyes can also change color over time. I have a black cat that started with two yellow eyes as a kitten, one of which had a little orange splotch. Now that orange splotch has taken over almost the entire eye after 14 years, such that he effectively has a splotchy case of heterochromia. Far as any vet can tell( without dissecting the eye )it seems normal and his is not a unique case.
Yup, I agree. If he were really a pure Russian Blue, it seems unlikely he’d end up at a shelter.
My best guess is that someone in the vicinity has an un-neutered Russian Blue male cat or two who has occasionally gotten outside and had a little fun with the local ladies. He fits all the RB traits so perfectly except for the white splotch (and maybe the fact his eyes aren’t greening up well) that I’m wondering if he’s 3/4 RB, but I’ll never know for sure and it doesn’t matter.
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