First of all take an image!
Open it with Adobe Photoshop!
1)Take the Pen Tool:
2)Choose the hair and press Ctr+Enter:
http://imageshack.gr/files/rh3qhdzz82phh723ghwe.jpg[/img]
3)Make a new layer, The copy the selected area tha paste it on the new layer:
http://imageshack.gr/files/eqtkaddqlye0sraedw32.jpg[/img]
4)Then press Crt+U and choose the colour that you want:
http://imageshack.gr/files/a78oo49gwii65x48h065.jpg[/img]
5)The select the bloor tool and make it more realistic!
http://imageshack.gr/files/dk8v5ywhj3z41cukk30i.jpg[/img]
Thanx!