Once when out on field duty in Grafenwoehr a white guy in my unit got fed up with all the brothers walking around with “do rags”. He decided that he could be a cool one too. It went all the way up to the battalion SMG - who ended up banning it from everyone. As he should have.
Use to be a chart outside of the ships barbershop showing acceptable hairstyle/cuts for both white and black sailors. Anything else would not be allowed. Worked great.