A few selections from the history of color systems from the “eclectic bookart” blog BibliOdyssey. A particular favorite is this one by Tobias Mayer from 1758. (BibliOdyssey’s annotated archives are done entirely in del.icio.us and available here.) See more color systems at the online Color Museum and Prof. Hans Irtel’s “Color Systems” site. A great classical essay on color is Wittgenstein’s book on the subject; a great contemporary essay is James Goggin’s “In Living Color” for Dot Dot Dot #6. My thoughts on arranging books by color are here.