What's with all the pseudo-psychological mumbo-jumbo?
There are perfectly objective ways of defining certain
colors, using chemistry and (gasp!) physics:
-- sodium yellow
-- neon red
-- cobalt blue
-- Tyrian purple
Whether or not such-and-such person can see a particular color
is irrelevant.
1) The physics of colored lights is fairly simple.
1) The physics of dyes and pigments is more complicated. The
general case is a black art, but certain special cases are
manageable, notably the mixing of modern printers' inks. Get
yourself a set of color chips, i.e. go to the graphic-arts
supply store and buy a copy of the Pantone Process Color
System Guide ... that will give you a set of industry-standard
colors.
3) The perception of pigmented objects under varying illumination
is very complicated. There is an entire field (psychophysics)
that deals with such issues. To get started, you could search on