I would think you'd need several different skullcap textures, for different color hair. Brown, blond, red, black, maybe gray. If someone made a pack like that, I would buy it. As long as it was low-res enough for dynamic hair. Say, under 300 polys.

Jack, collision detection may or may not work with hands. A low-res figure and hair are very important with dynamic hair, or Poser chokes. I don't know if collision detection would work properly on mesh as complex as hands. It probably depends on how powerful your computer is, and the resolution of the hair/models you are using.