Anytime someone makes a deliberately unusual or out of place decision about their public appearance, they are inviting you to make it your business. Melania can't even wear a jacket without the entire country speculating about the meaning. Face tattoos send a message. Public nudity sends a message. Suits and ties send a message. Beards and flannel send a message.
Of course people will judge you based on the appearance you choose to portray, that's what appearances are for. I find it slightly disingenuous to claim that we should all be able to look however we want to look, free of judgement. I want my waiter to look clean and my mechanic to look dirty, and if they choose to subvert that expectation then they can expect me to notice, and to form opinions based on their unusual choices.
Hair color is no different. Weird colors are totally normal in some circumstances, and jarring in others, and any time someone chooses the jarring circumstance they have invited your judgment, no different than if they had chosen all black leather or a pink tutu. We all use our public appearance to send important social cues.
So yea, it's kind of everyone's business. You don't get to say anything (that's rude) but you totally get to have an opinion.
If my accountant shows up for a meeting in a gimp costume, am I supposed to pretend I don't notice? I'm all for respecting personal life choices, but it seems silly to pretend appearances don't matter.
Pretty much this is what I was trying to say. As regarding the comment about someone being plus sized, we have the right to judge them for that too. Many of us work very hard at fitness and what we eat so as to specifically not be obese. Among Mustachians, someone who manages money extremely stupidly would be frowned on, as that is a negative behavior, and if such a person were to seek validation for their poor life choices, I would be well within my right to withhold approval. Well, being overweight carries increased risks of heart disease, diabetes, and all other sorts of health risks and it is fair to consider such unattractive. Furthermore, this is a risk factor that is completely controllable by the person as the steward of their own body, and yet we don't charge obese people more for health insurance even though we do charge young people more for car insurance, or people who live in flood planes have to buy flood insurance because regular homeowners' insurance won't cover flood damage.
People can do what they want, but there are certain judgments that people will make when they do. These are judgments that are sometimes hard coded into us from evolution, and other times bcome a part of us subconsciously as we experience the world and learn a set of judgments and patterns that help us navigate our world as adults.
My belief is that some women can pull off the look, and others can't. My belief is that guys can't. The women that are able to pull it off, it's because it's part of an overall appearance. The photos I posted (removed, due to legit comments about their sharing on the internet) showed a cyberpunk girl whose red hair fits into her overall appearance. The second showed a girl going for a chic grungy style of fashion with blue hair, and the third showed an otherwise normal college kid who decided to make a "radical fashion statement" by dying their hair but continues to dress generally conservatively.
In my experience, people who simply change their hair color and it's not part of an overall lifestyle are just seeking to break from a dull reality and otherwise generate attention for their "lifestyle change." There is no shortage of people out there willing to notice the hair color, make conversation, and because people tend to be non-confrontational in public, offer a compliment on the style (even though they'll later tell you they think it looks bad when the person isn't around). This validation is no different than people who post positive statuses on social media seeking validation. It reeks in many ways of desperation, in my opinion.
And it's not just picking on hair color. Men do this stuff too. Investment bankers suddenly showing up with leather jackets or wearing camo at places where this is not appropriate. Spending a bunch of money on fancy sunglasses, etc. If appearances truly aren't that important, and I'm being JudgyMcJudgyPants by saying that appearances signal certain things to me, then why do the same people who criticize me for judging a person's BMI (the reduction of which actually is statistically correlated with lower healthcare usage and therefore lower costs) advocate for squandering wealth in the pursuit of changing or perfecting appearances through dyed hair, man buns, etc.?