This isn't necessarily about hair, but when I went through rush in the fall, I was cut from at least one sorority because I have a lip ring. The sorority I know I was cut from for that reason was the one with 10+ of my friends, one of which cried when they cut me after the first day. The chapter advisor wouldn't let them take on any girls with facial piercings or oddly colored hair.
I did find a sorority who accepted me for who I am, which is great! It really hurt to have a 3.75 GPA, been a member/leader in 7 clubs in High school, and graduated early, but still not being "good enough" because of a lip ring. Oh well. The girls in that sorority and I are still great friends, so it all worked out.