Except for a tetrachromat. Specifically, a strong tetrachromat that has both four colour channels in the brain and a different frequency on the fourth cone.
Who are, admittedly, hella rare. Apparently there are less than a few dozen confirmed world-wide.
But they do exist.
What's actually hella rare is tests for tetrachromacy. Given the total number of people who have ever taken such a test, I think it's reasonable to assume there are significantly more than a few dozen actual tetrachromats out there.
> More precisely, she had an additional cone type L′, intermediate between M and L in its responsivity, and showed 3 dimensional (M, L′, and L components) color discrimination for wavelengths 546–670 nm (to which the fourth type, S, is insensitive). Source: Wikipedia
Do they?
"Genuinely remarkable. You sailed past the theoretical human limit like it owed you money. I'd accuse you of cheating but I don't actually know how you'd cheat at this."
I can see what they mean about .02 though. If I weren’t specifically looking for difference that’s where the colors become less noticeable.
There's was 2 or 3 where i had no idea, guessed and was a way off.
There's was 1 where i did a hail Mary and got it. It was interesting how some even towards the end were really obvious and others were really subtle - I'd say I did better with purple tones and worst with the blue / greys.
I need a better display for sure :)
“Show HN: What's my JND? – a colour guessing game” 54 points | 8 days ago | 62 comments