Talk:Primary color
" This is also lends some insight into why visible-light lasers tend to be only red, green, or blue. using combinations of colors creates frequency interference, causing the beam to become decollinated and to spread apart quickly. (But does it explain why lasers aren't orange, yellow, or cyan? Those colors can also be created with one wavelength.)"
There is nothing fundamental about these colors, they're just wavelengths. Color is arbitrarily determined by in the eye, depending on the intensity of the signal in one of the six different types of cone groups. For a quick proof by counterexample, the maser was invented before the laser (maser stands for Microwave Amplification by Stimulated Emission of Radiation, and has no color whatsoever)--BlackGriffen
I also removed:
This is the reason that television uses red, green, and blue phosphors. Any color combination can be represented by mixing different proportions of the primary colors. Note that in practice this is restricted by technical limitations of the medium, for example the television standard NTSC is noted for its inability to represent certain colors to retain backward compatibility with black and white televisions.
This isn't true at all. There's really no such thing a "primary" and "non-primary" color--the primaries are just whichever ones you choose to call primary, and the colors they can make with mixing are only those within the gamut of those your choose. Some make better choices than others, but let's not make it sound like there's some special property of red, green, and blue that make them magical or something. --LDC
What makes red, green, and blue special is that they correspond to the peak responses for the human eye's photoreceptors. Is that right? --Damian Yerrick
Well, yes, there is that. But the primaries typically chosen for TVs and such don't correspond exactly to the peaks of the cones' responses, but to colors that are pretty close and that have cheap available phosphors. And you really can stray pretty far from the actual human visual primaries and still get a good gamut. And non-human eyes may have entirely different primaries--birds have four, for example. --LDC
Red, green and blue are not the peak responses. The wavelengths of the peak responses are given in the color article. You choose red, green and blue light because you get the biggest part of the human color space that way. Red light for instance is lower in frequency than the "red" cone's peak frequency in the eye so that it won't create a response in the "green" cone (the cone's response curves overlap). There is a definite biological reason why red, green and blue light are the additive primaries for human color vision, but it's not the peak responses.AxelBoldt