
Must be their natural, inherited, lifelong skin tone. Must be most of their body, not just a small patch.
I will only count people for whom I have strong evidence of their color; ideally a photograph. Verbal or artistic descriptions can count but only if it's unambiguous that they were a shade that qualifies. People take a lot of liberties when describing skin tone (no humans are actually "white" or "black"), and people find it remarkable and worth exaggerating when someone is even only slightly different from the norm. So I don't trust simple statements of color like "she was blue", since that probably just means "she was slightly bluer than the human average of 'not at all blue'".
People are also trading
@JussiVilleHeiskanen If that were a genetic condition (which it is not) it might be blue enough to qualify, yeah. Not sure though, it's still pretty greyish.
@EricNeyman Yeah I'm looking into them but I can't find a single photograph to confirm how colorful they actually were.
@JussiVilleHeiskanen That is not a blue fugate, nor is that even a genetic condition at all; that person did it to themselves by rubbing silver on their skin.
https://en.wikipedia.org/wiki/Paul_Karason
Please do not simply take the first image you see from Google without any attempt to fact-check it, and present it as though you have uncovered useful information. We are all capable of using Google image search.
Ok, here is one photo that's claimed to actually be of a blue Fugate:

(There's also a very old photo that's in black-and-white so is useless, and there are some recent photos of people from the family who just look normal because they've been cured or didn't inherit the lifelong form of the condition. (Many of them were only blue as babies.))
I don't think this counts. That woman is grey, not blue.
Hah, and even that picture is probably fake. Big news articles attribute it to "The Lost Creek Medicine Show", which it turns out is somebody's blog. This person does not explain where they got this photo, and other blog posts of theirs are stories about hauntings and paranormal phenomena with qualifications like the following:
I wasn’t there so I have no idea if their claims are true or not. For my purpose that is beside the point. It’s a really good story whether it actually happened or they made it all up. If they did, they deserve the money they made off books and movies. We make authors and screenwriters rich don’t we?
@IsaacKing I meant like a genetic change that could be inherited, rather than one that only effects the one person who gets it.
@digory Oh, duh. Yeah I think it's not really "natural" if it's not inheritable. They need to be colorful in roughly the same way that most people are brown.
@spiderduckpig yes, I was born bright yellow for one. Or that is after they washed all the shit away.
There are folks who are blue and there are green dudes as well. Also, do illustrated people count? Sorry, reread the description. Has to be genetic. Okay