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LED screens in televisions and smartphones use pixels that use a combination of Red, Green, and Blue diodes that can produce any color when used in the correct proportion of intensity.

My question is, do these Red, Green, and Blue have any specific wavelengths? If so, what are they?

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  • $\begingroup$ The wavelength band of each color like Red, Blue, Green, etc have very small range of around 20-30 nm. So you could just look up the wavelengths here and here. LEDs don't emit any "special" Red/Blue/Green. $\endgroup$ – user139621 Aug 25 '17 at 12:49
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    $\begingroup$ @Blue If the RGB wavelengths aren't clearly specified, then doesn't it mean the very RGB scheme to identify colors is pointless? If my red, green, and blue don't match your red, green, and blue; if I say "RGB: (234,36,121)" we both will percieve it as two different colors, isn't it? $\endgroup$ – Pritt Balagopal Aug 25 '17 at 13:11
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    $\begingroup$ To get 'true color' for a display, you have to calibrate it. As for color perception, that is a philosophical question (see Wittgenstein). $\endgroup$ – Jon Custer Aug 25 '17 at 14:02
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    $\begingroup$ Yes, yes they will. And that is why you need to calibrate individual displays for serious color work. Most of us don't bother because it doesn't matter for what we do. $\endgroup$ – Jon Custer Aug 25 '17 at 15:28
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    $\begingroup$ No. You get a selection of Pantone color swatches, compare your monitor to them, and the Pantone application basically works backwards from those comparisons to change the color mapping of your system to account for the display properties. Then, when your graphic arts application calls for Pantone color #xyz, the display driver puts out the appropriate (RGB) combination to display that exact color. But, typically only heavy duty graphic artists do this. Just about anybody can tell that two non-matching monitors don't display the same colors. If you use two monitors, always buy in pairs! $\endgroup$ – Jon Custer Aug 25 '17 at 15:39
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Most modern TV/computer screens don't have so saturated RGB primary colors to name any particular triple wavelengths as the wavelengths of a particular monitor. Moreover, if we try to ascribe some wavelength to a primary color by applying the concept of dominant wavelength, we'll still have too much variation in actual RGB primaries in different screen technologies.

The most common color space to which the computer monitors (and, to a lesser extent, TV screens) adhere is sRGB. There we have dominant wavelengths of about 549 nm for green, 612 nm for red and 464 nm for blue with respect to the sRGB white point.

On the other hand, there are many displays like OLED TVs and smartphone AMOLED screens, which use another (more saturated) set of primary colors, e.g. Display P3. In this color space the dominant wavelengths are close to those of sRGB, but somewhat different.

And even among the displays which nominally correspond to the same color space standard, there's quite a noticeable variation of primary colors and the proportions in which they are mixed for any given RGB value. So if you have two monitors (especially of different makes or models) and try to display the same color on them, you'll notice that the colors don't match.

Color calibration is a procedure with which we can try to minimize differences of the colors displayed by a monitor from the reference color space, but if monitor's primaries are too far from the nominal, this won't lead to too good results, so some residual mismatching will still remain.

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Wikipedia has a beautiful chart which should clear up your misunderstanding. Basically, there are a variety of compounds which may be used to create a particular color. Since no single option functions significantly better or cheaper (at any given perceived color), and humans can perceive the full range of colors from a linear combination of 3 reasonably chosen single colors, there has been no standardization.

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