Brandlin,
For many years I was using enamels, but these last few years I've been using acrylics...
I routinely use just five. Zinc white, Burnt umber, Cadmium yellow, Cadmium red, and black. The skin tone is achieved with a mix of brown, yellow, black and white, with a touch of red. A peat brown ink wash is used for lowlights... This gives a range of greenish brown to reddish brown skin tones not unlike the leathery looking skin tones used for the UrukHai in the PJ films.
I have a bucketload of dwarves on order from Em4 as we speak