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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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    $\begingroup$ @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? $\endgroup$ Aug 25, 2017 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, 2017 at 14:02
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    $\begingroup$ @JonCuster Apologies, perception wasn't what I meant to say. But if the wavelengths differ, won't the resultant RGB color code give different colors on different screens? $\endgroup$ Aug 25, 2017 at 15:25
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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, 2017 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, 2017 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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I think the answer depends on the technical specifications of the monitor, and the exact frequency emitted by the LEDs or whatever light source.

RGB monitors combine to create the illusion of wavelength, by stimulating our short, medium and long wave light sensitive cells. So the color we perceive is NOT the wavelength. It's the illusion of that wavelength. If you combine red and green to make yellow, you get the red wavelength (610 nm) and the green wavelength (500 nm), but this does not create a yellow wavelength in between. Yes our eye interprets the color yellow, but that's without any actual yellow light at (555 nm).

Unlike a light therapy device that emits light at the exact wavelength, monitors emit a combination of light to create the illusion that we see that wavelength, when we're seeing a combination of colors at different wavelengths that have the same visual effect.

So I think the answer is to go to the data sheet of the LEDs or whatever light source use, on a monitor by monitor basis. Basically, it's a big research job to figure out.

I wanted to get this data, so if anyone knows where to find it, please post to the group.

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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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