I mean, who wouldn't be? Pigments, of course, are the colored powders that give paints their, ur, their color. Without pigments, paintings wouldn't look like much. Cars, houses, and billboards would be pretty boring to look at as well.
One good, easy to digest reference on the web is the Pigments Through the Ages site. It is simple and easy to navigate. While not exhaustive, it reviews a range of historical (and some modern) pigments. It discusses their history, tells where (if natural) they are found or how (if manufactured) they are made, shows how they are made or processed, provides information about their chemical makeup, and so on. It doesn't cover as many pigments as I would like, and it leaves out some detail, but I'm an art geek. If you just want to browse through and get some interesting information, this is a nice little site.