Question for Pentecostals?

I am Pentecostal, but not Apostolic. Can someone explain to me why you believe it is wrong for a woman to color and cut her hair? I know in the Bible it says that a woman must not shorn her hair.. when you shorn a sheep, it means cutting really close to the body, if not shaving the whole thing. So does it just mean that woman should not cut their hair that short? Or does it mean women shouldn't cut their hair altogether?