VisiBone Anglo-Centric Color Code
Peter Hamer correctly points out that this naming scheme should not be confused with names given to spectral colors, such as those that follow the mnemonic Roy G. Biv: Red, Orange, Yellow, Green, Blue, Indigo, Violet. The distinction is between the physical nature of light and the human perception of if.
Humans cant distinguish yellow light from a mixture of red and green light. Thats due to the color detection mechanism of the human eye. The cones on the surface of the retina respond differentially to red, green and blue light. (The rods on the other hand are very sensitive to the brightness of light but cant distinguish hues.) So computer phosphors dont attempt to transmit yellow light at all. They simulate it by transmitting both red and green. At least humans can be fooled in this way.
Theres much more to light than the human eye can measure. Besides the fact that visible light is a narrow subset of all the light coming from the sun, there a whole dimension in the variation of frequency and amplitude to which the eye is tone deaf. This dimension is important to astronomers and chemists. Their instruments measure aspects of light that can reveal, for example, the composition of a star as well as that of a material found at a crime scene.
Only when light is for eyes only, yours or anyones, can we simplify theory and measurement to varying quantities of red, green and blue. (Ever use a magnifying glass on your computer screen to see the little dots? Watch that eyestrain! Didnt I say a magnfying glass?!) So the physics of color and the perception of color are different disciplines.
Another interesting distinction, hues on a computer monitor as well as in the mind of a user, follow a circular series, as named above in the hue list. Magenta and Pink are as close to each other in perception as Green and Teal. But the physics of light is linear, a spectrum. Violet in the color spectrum is the furthest thing from Red. With real light, theres no such thing as magenta. The eye, when the red and blue cones are stimulated sees magenta, but it doesnt correspond to any frequency of light, the way most other hues do.
Incidentally, the distinction between Red, Green, Blue (RGB) and Cyan, Magenta, Yellow (CMY or CMYK when Black is added to the mix) is purely tactical. Printers use light-absorbing ink and computer monitors use light-transmitting phosphors. The perfect cyan ink would completely absorb red light and be completely transparent to green and blue. The tactic of mixing cyan and yellow ink to get green is backwards from mixing red and green light to get yellow. But the strategy is the same: fooling human eyeballs by manipulating the red, green and blue light that ultimately hits the retina.