By that I mean hair 100% free of perms, straighteners, chemical colors and lighteners. Temp color doesn't count because it does get washed out in about 8 weeks. However if a permanent process has occurred the only way to be rid of it is the scissors. So if your hair was 12" long when you colored it and that was four years ago in order for it to be virgin you'd have to cut that original 12" off. Most often you can easily tell by the line of demarcation.
As a stylist I went in the opposite direction most stylists do. My hair is to my butt crack and is completely virgin. I was wondering if anyone else has virgin hair of significant length or any length...but keeping it virgin at a longer length is considerably more difficult.