From what I know, Eddard's hair is black. Or was it dark brown? I don't remember. I bet on black, though. And he was 25 by the time A Game of Thrones happened.
I would hope that Eddard Stark would be considerably older than 25 in A Game of Thrones, since his eldest son Robb is 15. That would put Eddard at being 10 years old when he fathered Robb and led the North to war, no less that he somehow held his own in combat against Arthur Dayne at the Tower of Joy.
I think that him being in his thirties is most likely. He's supposed to be younger than Brandon, so it's believable that he was only 16 or 17 when he married Catelyn and fathered Robb, then went to war. Or even 15, it leads to an interesting correlation since Robb marries, fathers a child and goes to war when he's 15.
His hair is dark brown.
Oh, never mind. I checked and apparently he's 35 in a Game of Thrones, so he'd be 20 in the rebellion.
Edited by Anouleth, 10 April 2012 - 12:10 PM.