These are some notes that I took from old books on color printing
and color photography.
Originally posted to the Color Theory mailing list.
Part 1: Bibliography
Part 2: 2-Color and 6-Color printing
Part 3: Metamerism and other limitations
Part 4: Pleasing color vs accurate color
Part 5: History of unsharp masking,
moire in halftones
The book by Billmeyer & Saltzman is still in print (but expensive).
The book by Yule was re-issued by GATF in 2000, after being out of print for 20 years. Available from GATF or Amazon.