Langridge Artists Pigments are the pure pigments that are used in traditional artist paints; things like Burnt Umber and Ultramarine Blue etc. The prices vary depending on the particular pigment ("Series 1" pigments are the cheapest, then "Series 2" and so on). These pigments can be added directly to resin (in the same way that Mica Powder is used to colour resin). They can also be used to create paints by adding the appropriate binder (e.g. Linseed Oil for oil paint, Gum Arabic for watercolour, Acrylic binding medium for acrylic paint etc.)

This place (Cavalier Art Supplies) has the cheapest prices for these I've seen so far, with $9.90 flat rate postage within Australia.