I understand what you're saying, but I have a degree in sociology and loved my social statistics classes. So I'm really into statistics, cause and effect, and likelihood and predictability.
Women who color their hair in colors that aren't natural human hair colors are a subgroup, of their own choosing. (this is going to bore everyone to death) Any subgroup of people who "self select", that is, they're in that group by choice as opposed to groups of people with the same eye color, same initials, etc. have things in common that as a GROUP, you can predict. (At this point people usually jump up and start naming anomalies, things that surprisingly don't fit into the group, just to point out you can't predict individuals, but you can predict groups). So ok.
People who are PTA presidents have lots in common, people who are cat owners have lots in common, people who own sailboats have lots in common, etc. You can make predictions about populations of people although obviously there are red herrings out there who completely don't fit the mold.
When you see someone with the haircolor of MW, you can make some inferences that are very likely to be true. One of them, I believe, is that she's likely to have more odd or unsavory friends than people in her exact other circumstances who do not color their hair nonhuman colors.
I have two friends with nonhuman hair color, and they themselves are delightful and I love them to death. But BOTH of them have other dear friends who are dangerous. Not just quirky, that's great, I'm talking dangerous. So when I get together with these friends over a glass of wine, the subject of how these other friends are doing typically comes up - it's always an interesting story, always makes me glad that those people are not MY friends.
SORRY THIS IS LONG. But wouldn't you agree that people with nonhuman hair color are, in fact, more tolerant of other people behaving oddly, and more likely to have a few friends, a few connections who seem scary to the mainstream of society? People who are shunned by the mainstream for cause, and yet people with pink hair accept their friendship anyway and are connected to them?
Just my own observations on life.