Every kitten starts life blue-eyed, because the iris has not yet produced its adult pigment when the eyes open. Watching that blue give way is one of the small pleasures of the kitten weeks, and because the timing varies, owners often wonder whether a slow change means something is wrong. Usually it does not.
Why kitten eyes start blue
The blue is not a pigment at all, but the appearance of an iris that has not yet filled with melanin, the same pigment that colours fur and skin. As a kitten grows, pigment-producing cells in the iris become active, and the eventual adult colour — green, gold, amber, copper, or, in some cats, a permanent blue — depends on how much pigment arrives and on her genetics. Colourpoint cats and many white cats retain blue eyes as adults precisely because their pigment pattern leaves the iris uncoloured, so blue at six months is not automatically an unfinished change.
The usual timeline of the change
Eyes open in the second week of life, already blue, and the first hints of change typically appear around six to seven weeks: a ring or flecking of a new colour near the pupil, or one patch of iris altering before the rest. Over the following weeks the new colour spreads unevenly, which can leave a kitten temporarily with marbled or mismatched-looking eyes that are entirely normal mid-transition. For many kittens the colour is largely settled by around three months, though subtle deepening can continue beyond that, and late developers whose change only completes nearer four months are well within the ordinary range.
What a late or uneven change can still be
A late change by itself — in a kitten who sees well, plays, tracks toys, and has clear, comfortable eyes — is a variation, not a warning sign. Two different finished colours, one blue and one gold, also occur naturally in some cats and are usually present from this same transition. What deserves a veterinary look is change accompanied by something else: cloudiness over the eye, redness, squinting, discharge, a pupil that stays a different size from its pair, or an older cat whose settled eye colour suddenly changes. Those are changes in the eye's health, not its pigment timetable, and they should be examined rather than watched at home.
Tracking development at her early checks
Breed and coat pattern offer useful expectations here: colourpoint kittens keep their blue, many silver and smoke kittens finish green or gold, and orange kittens most often settle into gold or copper eyes. Knowing her parents' eye colours, when they are known, gives a fair preview of where her own change is heading. None of these predictions replaces watching the eyes themselves stay bright and clear through the transition.
Her first veterinary visits fall right in the middle of this transition, so mentioning an unusually slow change there costs nothing and puts a professional eye on it. Photographing her face in similar light every couple of weeks gives you an honest record of the shift, since memory tends to insist nothing has changed until suddenly everything has. Those dated photos and check-up notes become part of the development picture her vet reads at later visits. Keeping each of those early records together in KinsLe Pet Passport means this kitten's eye-colour change sits alongside her weights and health checks in one packet for every appointment.