question: If the primary colors are Red, Blue, and Yellow, why are displays and televisions built on a Red, Blue, and Green color standard?
comment: Because there are 2 different sets of primary colours. When you're mixing pigments (like paint) the primary colours are red, blue and yellow (or magenta, cyan and yellow) When you're mixing light (different wavelengths), the primary colours are red, blue and green (and because the tv works by emitting light, that's the standard they use)
passages: The exact colors chosen for additive primaries are a technological compromise between the available phosphors (including considerations such as cost and power usage) and the need for large chromaticity gamut. The ITU-R BT.709-5/sRGB primaries are typical.
   Additive mixing of coincident spot lights was applied in the experiments used to derive the CIE 1931 colorspace. The original "monochromatic" primaries of the (arbitrary) wavelengths of 435.8 nm (violet), 546.1 nm (green), and 700 nm (red) were used in this application due to the convenience they afforded to the experimental work.
  
  Red, green, and blue light are popular primaries for additive color mixing since primary lights with those hues provide a large triangular chromaticity gamut. Small red, green, and blue elements in electronic displays mix additively from an appropriate viewing distance to synthesize compelling colored images.
   Using today's three-phase electrical system in an analogy, overlaying an R-, G- and B-color TV signal management system upon an existing monochrome TV signal management system would be analogous to requiring public utility power systems to convert from three-phase to nine-phase electricity, an insurmountable cost penalty.
   All sets of real and color-space primaries are "arbitrary", in the sense that there is no one set of primaries that can be considered the canonical set. Primary pigments or light sources selected for a given application on the basis of subjective preferences as well as practical factors such as cost, stability, availability etc. Color-space primaries can be subjected to meaningful one-to-one transformations so that the transformed space is still complete and each color is specified with a unique sum.
   Thus for trichromats like humans, we use three (or more) primaries for most general purposes. Two primaries would be unable to produce even some of the most common among the named colors. Adding a reasonable choice of the third primary can drastically increase the available gamut, while adding a fourth or fifth may increase the gamut but typically not by as much.
   The mixture of equal amounts of these colors produce the secondary colors red, blue, and "lime" green (the RGB primary colors of light), as follows:
  
  That is, the primary and secondary CMY colors (with secondary colors in boldface) are: 
  
  Ideally, combining three perfect primary colors in equal amounts would produce black, but this is impossible to achieve in practice. Therefore a "key" pigment, usually black, is added to printing to produce dark shades more efficiently. This combination is referred to as CMYK, where K stands for Key.
  
  Section::::Subtractive secondaries.:Traditional painting (RYB).
   Media that transmit light (such as television) use additive color mixing with primary colors of red, green, and blue, each of which stimulates one of the three types of the eye's color receptors with as little stimulation as possible of the other two. This is called "RGB" color space. Mixtures of light of these primary colors cover a large part of the human color space and thus produce a large part of human color experiences. This is why color television sets or color computer monitors need only produce mixtures of red, green and blue light. See Additive color.
   The color defined as blue in the RGB color model, X11 blue, is shown at right. This color is the brightest possible blue that can be reproduced on a computer screen, and is the color named blue in X11. It is one of the three primary colors used in the RGB color space, along with red and green. The three additive primaries in the RGB color system are the three colors of light chosen such as to provide the maximum gamut of colors that are capable of being represented on a computer or television set.
   Section::::Direct color.:More than 3 primaries.
  
  Virtually all television displays and computer displays form images by varying the strength of just three primary colors: red, green, and blue. For example, bright yellow is formed by roughly equal red and green contributions, with no blue contribution.
   These are generic complete repertories of colors to produce black and white and RGB color pictures by the display hardware, not necessarily the total number of such colors that can be simultaneously displayed in a given text or graphic mode of any machine. RGB is the most common method to produce colors for displays; so these complete RGB color repertories have every possible combination of R-G-B triplets within any given maximum number of levels per component.
   Most televisions, computer displays, and projectors produce colors by combining red, green, and blue light in varying intensities—the so-called RGB additive primary colors. However, the relationship between the constituent amounts of red, green, and blue light and the resulting color is unintuitive, especially for inexperienced users, and for users familiar with subtractive color mixing of paints or traditional artists’ models based on tints and shades.
   In order to organize the material, color palettes have been grouped following arbitrary but rational criteria. First, generic monochrome and full RGB repertories common to various computer display systems. Second, usual color repertories used for display systems that employ indexed color techniques. And finally, specific manufacturers' color palettes implemented in many representative early personal computers and videogame consoles of various brands.
   The color defined as "green" in the RGB color model, displayed on the right, is the brightest possible green that can be reproduced on a computer screen, and is the color named "green" in X11. It is one of the three primary colors used in the RGB color space along with red and blue. The three additive primaries in the RGB color system are the three colors of light chosen such as to provide the maximum range of colors that are capable of being represented on a computer or television set.
   Section::::National standard.
  
  The National Television System Committee, NTSC, standard was the analog television system that was used in most of the North America from 1941 until the mandatory cutover to ATSC in 2009. However, low-power TV stations were permitted to operate with NTSC, for now, but many have since converted to ATSC. This national standard was later adopted (or, in some cases, adapted) in other jurisdictions, such as Japan.
   Similarly, most human color perceptions can be generated by a mixture of three colors called "primaries". This is used to reproduce color scenes in photography, printing, television, and other media. There are a number of methods or [[color space]]s for specifying a color in terms of three particular primary colors. Each method has its advantages and disadvantages depending on the particular application.
   [[Additive color]] is light created by mixing together [[light]] of two or more different colors. [[Red]], [[green]], and [[blue]] are the additive [[primary color]]s normally used in additive color systems such as projectors and computer terminals.
  
  Section::::Spectral colors and color reproduction.:Subtractive coloring.
  
  [[File:SubtractiveColor.svg|thumb|Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black]]
   xvYCC was motivated by the fact that modern display and capture technologies often have underlying RGB primaries with significantly higher saturation than the traditional CRT displays, allowing them to handle a wider color gamut. But these devices have been unable to do this without upsetting basic calibration, as all existing video storage and transmission systems are based on CRT primaries, and are hence limited to the CRT gamut.
   Elementary art education materials, dictionaries, and electronic search engines often define primary colors effectively as conceptual colors (generally red, yellow, and blue; or red, green, and blue) that can be used to mix "all" other colors and often go further and suggest that these conceptual colors correspond to specific hues and precise wavelengths. Such sources do not present a coherent, consistent definition of primary colors since real primaries cannot be complete.
  
  Section::::Additive mixing of light.
   See further details in the summary paragraph of the corresponding article.
  
  Section::::List of monochrome and RGB palettes.
  
  For the purpose of this article, the term "monochrome palette" means a set of intensities for a monochrome display, and the term "RGB palette" is defined as the complete set of combinations a given RGB display can offer by mixing all the possible intensities of the red, green, and blue primaries available in its hardware.
   The color displayed at right, "red (RGB)", "RGB red", or "electric red" (as opposed to "pigment red", shown below) is the brightest possible red that can be reproduced on a computer monitor. This color is an approximation of an orangish red spectral color. It is one of the three primary colors of light in the RGB color model, along with green and blue. The three additive primaries in the RGB color system are the three colors of light chosen such as to provide the maximum gamut of colors that are capable of being represented on a computer or television set, at a reasonable expense of power. Portable devices such as mobile phones might have an even narrower gamut due to this purity–power tradeoff and their "red" may be less colorful and more orangish than the standard red of sRGB.
   Other primary colors could in principle be used, but with red, green and blue the largest portion of the human color space can be captured. Unfortunately there is no exact consensus as to what loci in the chromaticity diagram the red, green, and blue colors should have, so the same RGB values can give rise to slightly different colors on different screens.
  
  Section::::Additive and subtractive color models.:CMYK color model.
   In the past, manufacturers have developed many different display systems in a competitive, non-collaborative basis (with a few exceptions, as the VESA consortium), creating many proprietary, non-standard different instances of display hardware. Often, as with early personal and home computers, a given machine employed its unique display subsystem, with its also unique color palette. Also, software developers had made use of the color abilities of distinct display systems in many different ways. The result is that there is no single common standard nomenclature or classification taxonomy which can encompass every computer colour palette.
   Secondary color
  
  A secondary color is a color made by mixing of two primary colors in a given color space.
  
  Section::::Additive secondaries.
  
  Section::::Additive secondaries.:Light (RGB).
  
  For the human eye, good primary colors of light are red, green, and blue. Combining lights of these colors produces a large range of visible colors.
  
  That is, the primary and secondary RGB colors (with secondary colors in boldface) are: 
  
  Combining RGB colors means adding light (thus the term "additive color"), and the combinations are brighter. When all three primaries are combined in equal amounts, the result is white.
   Cyan, magenta, and yellow are good subtractive primaries in that idealized filters with those hues can be overlaid to yield the largest chromaticity gamuts of reflected light. An additional "key" ink (shorthand for the "key printing plate" that impressed the artistic detail of an image, usually black) is also usually used since it is difficult to mix a dark enough black ink using the other three inks. Before the color names "cyan" and "magenta" were in common use, these primaries were often known as blue and red, respectively, and their exact color has changed over time with access to new pigments and technologies.
   The three axes of the psychological primaries were applied by Richard S. Hunter as the primaries for the colorspace ultimately known as CIELAB. The Natural Color System is also directly inspired by the psychological primaries.
  
  Section::::History.
  
presuppositions: Displays and Televisions should use the primary colors. There is one set of primary colors for both pigments and light.
corrections: There are two sets of primary colors, and tvs use the primary colors for mixing light. There are two sets of primary colors: one for pigments and one for light.
raw_presuppositions: Displays and Televisions should use the primary colors. There is one set of primary colors for both pigments and light.
raw_corrections: There are two sets of primary colors, and tvs use the primary colors for mixing light. There are two sets of primary colors: one for pigments and one for light.