Hair is just hair. People, men and women, should be able to wear it how THEY like it. Period.
When my oldest son started to grow his hair long in 8th grade, people kept asking me when I was going to “make” him get it cut. I would always tell them it was up to my son. It was HIS hair, and if he liked it, then I was OK with it. My only stipulation was that he kept it washed and clean. He kept it pretty long until his senior year of high school, then cut it.
My middle son (18 years) has hair longer than I do (mid shoulder length). He is very particular about his hair. He has one stylist that he sees to get it thinned and trimmed every few months, and he has a complete hair regiment he goes through every day. He gets sooo many complements on his hair, ironically enough, mostly from older women! He has worn it long since he was about 13.
My hair must be long enough to pull into a pony tail or short enough that it does not get in my eyes. No in between!
As for color - again, if the wearer likes it, go for it! It is JUST HAIR!
JMHO.