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Thanatomanic t1_iu15xpx wrote

This is not how it works. Most monochromatic colors fall way outside the color gamut of a typical display, and are therefore impossible to show accurately.

For example, see this image: https://upload.wikimedia.org/wikipedia/commons/thumb/9/91/SRGB_chromaticity_CIE1931.svg/440px-SRGB_chromaticity_CIE1931.svg.png Your phone can probably show you all colors within the triangle. But monochromatic light traces the outline of the weird shape.

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Vreejack t1_iu2lldw wrote

One obvious flaw is that--for example--pure blue is 440nm, and you get that on the display by showing only bright blue pixels with no red or green. It is impossible to show a bluer color than that on your RGB display. Anything to the left of that on the chart would be "bluer", meaning it has even less green and red than 440 does, but you are already at the limit of the display, which demarcates the limit of you monitor's color gamut. Adding red in, as the chart does, makes no sense.

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[deleted] t1_iu3haks wrote

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TossAway35626 t1_iu3l1a9 wrote

Fun fact, its only due to a weird quirk of biology, an imperfection, that red and blue make purple. Were it not for this we would have a completely different color wheel.

The cone that picks up red also picks up just a bit of violet. So if something triggers both our red and blue rods, it must be purple. Our eyes cannot tell the difference between a single wavelength triggering red and blue and 2 wavelengths triggering red and blue, it sends the same purple signal to our brain either way.

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[deleted] t1_iu3lk5q wrote

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TossAway35626 t1_iu55mg9 wrote

I do not remember that comment, I should stop redditing before bed.

I feel describing cones by the colors they pick up makes it easier for people to understand. Not sure what was going through my head when I said rods though, I referred to them correctly earlier in the comment.

I would actually like to see monochromatic violet next to red and blue to see if there's an actual difference. Its not exactly possible to imitate this experiment with a screen.

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Any_1ove t1_iu1rgac wrote

I was wondering why it looked different. Thanks!

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[deleted] t1_iu3hegy wrote

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Thanatomanic t1_iu3iy3x wrote

That all depends on the color space and transformation you use for your gamut mapping.

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[deleted] t1_iu3k58q wrote

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Thanatomanic t1_iu3kain wrote

Even with sRGB as default and a well-calibrated display, the choice of gamut transformation determines the hue that you get on your display in comparison with the monochromatic light. It's really not clear cut.

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RoastedRhino t1_iu3viy6 wrote

Well, it's pretty clear that if my monitor has three leds, each one emitting light at different frequencies, the only thing that they can produce is the sum of lights at those frequencies, not another frequency.

And viceversa: there are colors that come from mixtures of frequencies and you cannot have with one frequency (purple).

Having said that, we only have three types of receptors, and it is possible to match the response of those as good as possible.

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