The cats are maybe 25% perception based, and can shift their appearances a specific direction, but it’s gradual and is really only used for their equivalent of transitioning to another gender. (even if the cats are pretty chill about gender presentation but sometimes an AFAB cat wants to be male, or vise versa, and that’s fine) it works like taking hormones only surgery isn’t necessary and they can even shift their insides if they want to switch all the way.
But color vision is way more refined and you can’t just magically manifest color cones just like cats who’s Waking Form has no leg from birth can’t just regenerate that leg.

I’ll explain this better in a future Manny Explains page once this chapter’s over, by then I should have a better idea of how to do it in a way that makes sense

(also I don’t want to be that author who just magically erases disabilities like…the cats might have crazy tech levels and supernatural powers but they can’t fix everything and sometimes even the powers in themselves can cause some problems. Good thing the healthcare system is awesome here and there’s plenty of accommodations to help every cat preform at their best and thrive despite their disabilities.)