I'm playing on a PC, it happens using FS and the SL viewer. So far I've only found 2 affected hair styles, not from the same maker. Other styles from the same maker don't do this.
When I land at this one place my hair is blonde as usual. Sometimes though, as soon as I move it turns white. Flying out of the area changes it back to blonde, and it's blonde when I fly back into the area, until I land and it turns white again.
I can easily fix it by taking off the hair and attaching it again.
When my hair is white most people see it as blonde still. Only one other person sees it turn white and she has the same issue with her eyes turning white.
It's not a huge problem, but it has a lot of people confused and we'd love to know why please.