Where is hair texture referenced?

[Dymitrix]

I have been searching for hours and can't seem to find any information on this.  I'm looking to add additional (not edit) hair colors.  I can't find where the hair color texture is referenced... I check both client side and server side.  The closest thign I got was in chargrp.dat on the client side.  It list the hair mesh and the textures, but only the first texture.  Where does it pick up info on the other textures?

 

Anyhow help would be greatly appreciated.  Thanks~