What exactly you are doing and problem(s) you're having? Just tested and it's working fine for me.
are you referring to the default hair? if you want to use a default hair, in the hair tab you'll probably see a button that says "back to hair selection" or something [it looks more like regular text though. -click it -choose the new hair you want -then choose the desired colors -scroll down to the "show on avatar" button -under the avatar, you'll have 2 options: "wear now" and "save to outfits"
If this doesn't work, there are many wigs available to choose from, with many styles and colors. and not all of them are expensive ;)
I really have to update my blog ObscureJourney and my review site BeingObscure. French speakers can read my reviews here.