You can definitely see it!

We had a regular black and white ultrasound with DD at 34 weeks and you could see a halo of hair floating around her head, clear as day. When they have alot of hair, and they're floating in fluid it "sticks up" so you can definitely see it.

I remember when she was starting to crown the midwife said "OH gee!! She's got LOTS of hair!!" and I said "I know!"...kinda ruined the motivation factor she was trying to give me