I use to have it where colored hair was more common than ‘natural’ colors, but I started to change it to match more of ‘real’ life, as when I was still in highschool, one out of 20 or so had dyed hair. Even then, it was died to a more natural color.
I wouldn’t stop reading a story if there was colored hair, but I might get a bit irritated if every. single. background. character. has dyed hair. (then all the main peeps don’t.) I haven’t come across that yet though.
Also, old people. Like senors, they don’t have lime - green hair xD