Yep, it bugs me too. It was black earlier in beta, but at some point during the beta it turned brown. Hopefully it'll get fixed 'cuz it's been reported a number of times and should be an easy fix.
It's always been this exact same color. How black it is depends on the hairstyle you choose, and the lighting you're viewing it under.
At this point it is what it is and should not be changed, as the game is live now and no longer in beta. Players creating new characters can easily avoid choosing this particular color if it doesn't appeal to them, where as people with existing characters who are already using this color might not appreciate having their choice suddenly change color in a patch.
And while there is a way to change your looks later on in the game, not everyone is at that point yet.