In article , Tim S wrote:
Andy Champ coughed up some electrons that declared:

wrote:

Red green and blue are defined scientifically as primary colors. I
don't know where those standards came from, nor do I care

You may not care, but I'm going to tell you anyway

It's from Biology, not physics; RGB are the peak sensitivities of the
three colour receptors in the most common human retina. We're so poor
at telling them apart that a red-green mix looks pretty much like some
kind of yellow. (Narrow spectrum lamps are fine for TV, but they can
make your wallpaper look a bit odd, which is one of the CFL problems)

Most common sort? Well, colour blindness is an obvious case. But
apparently a few women have 4-colour vision.

Just out of interest, what's the 4th colour?

Two different "green" receptors.
http://en.wikipedia.org/wiki/Opsin#C...2_opsin_groups
With two different X chromosomes it's possible to have both
OPN1MW and OPN1MW2.