Is it possible to clone a piece of hair to appear in two categories, say, grey hair and custom hair (in order to access "white" hair) without copying any graphics. I don't want to clone anygraphics because they are huge, and unnecessary. I think the definition starts with a GZPS Property Set, which then points to other files. If I were to copy a property set into a new file, could I have 2 hairs? What instance number is valid to pick?

For elders, or for multiple ages?

The easiest would be to make two separate recolors, BUT they can be texture-linked ("repo'd") if you don't want extra texture files.

If you want hairs to be separate from each other, they need separate *everything* when it comes to resources. They can be texture-linked via the TXMT (same way as clothes, hairs are often already texture-linked to some degree so they use the same resources).