Dynamic colorblindness correction
What I’ve figured out over the years is that my brain is always doing a bunch of tricky preprocessing on visual input to compensate for this. I’m not exactly sure what it does, but it works through subtleties in tone and decides whether something is red or green, and then plugs this color into my visual field, so that I see distinct and vivid shades of red and green (and blue).
J Rob Wheeler attempts to document the undocumented features of his color vision. I don’t have any trouble with blue, but my mild deuteranomaly causes me green/brown issues of the sort he describes. In particular, there are things which look green in one light and brown in another, and once clearly identified as one or the other, the assignment “sticks” in my head. (Unfortunately, this sticky information is not always correct: There is a sweater I have which my brain has decided is brown, even though in full-spectrum light it’s clearly a vine green. It just got stuck as brown, and so brown it will forever be.)