There are some material collections with quite a variety of different materials:

https://www.renderosity.com/marketplace/products/152329/ghostship-poser-12-materials-2

https://www.renderosity.com/marketplace/products/150836/ghostship2-poser-12-materials

https://www.renderosity.com/marketplace/products/158629/semi-precious-gemstones-for-superfly

https://www.renderosity.com/marketplace/products/136630/vb-supershaders-for-poser11-superfly-bundle (poser 11, but I think they work well enough in poser 12, too)

Vincebagnas materials can easily changed colour-wise, and ghostship's have options to plug in textures - especially useful for older dlothing textures.