Other possible names could be Barber or Hairdresser. A Hairstylist would be a NPC who changes a character's hairstyle for a small fee. For example, the NPC might charge 100 gold for a hairstyle change and 100 gold for a hair color change, and if a person wanted both, they'd have to pay 200 gold total. Such NPC's would be found in the larger cities only.
Also, seeing as there will be some form of NPC reaction to each person's character based on their decisions and personality, perhaps you could get discounts by being violent, nice, whatever else will exist in the game.
 But Why?
Yes I realise the existence of makeover credits in GW1 where you have to buy them IRL to be able to change your character appearance. But perhaps if that is continued in GW2, the makeover credits would only work for changing facial traits, skin color, body scale, and gender. Sometimes you just run into the problem that you don't need all that extra stuff and only want to change the hair color, and also find it a bit rediculous to spend money on something more than what you need. Also, for the campaigns if one were to want to change a character's hairsyle or color to one that is not from the campaign the character ws created in, one could purchase a 'Hair Unlock Pack' from the in game store, and then speak with a Hairstylist NPC, and change the hairstyle/color (of course if the GW1 campaign idea is not continued in GW2, then this would not be needed).
I've had this idea since I started playing GW, and it would be something I'd LOVE to see in GW2. I also know of many other people who would enjoy such a feature.
I'd love to hear your thoughts :) ~Cookies~