Commercially available viewing booths- standard illumination. Adjustment during separation-color correction. Understanding ink deficiencies. Yellow- best and purest pigment on the market. Major impurity- magenta, minor yellow.
Color being impure- pigment can still be chemically pure individual.
Process inks- vary from one to other manufacturer. Limited illumination restricts cones from sensing color. Every individual perceives color differently- based on differences in 6 million cones in eye. Cones- selective receptors of red, green or blue light or chromatic color. Human brain is not capable of remembering color or tone on absolute basis.