this post was submitted on 19 Jul 2024
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[–] MagicShel@programming.dev 35 points 3 months ago (2 children)

Yes.

Purple is not a single color. Maybe a spectrum analysis could answer this for a given instance of purple, but that's not my area of knowledge.

[–] deadbeef79000@lemmy.nz 26 points 3 months ago* (last edited 3 months ago) (3 children)

Specifically, purple is not a wavelength, unlike red(s) at ~700nm and blue(s) at ~400nm.

Purple is what human eyes see when the blue and red cones are both stimulated by their respective colours of light.

[–] AFKBRBChocolate@lemmy.world 11 points 3 months ago (1 children)

I like that some people are so confident in their incorrect understanding of something that they'll downvote the correct answer.

What you said is correct.

[–] deadbeef79000@lemmy.nz 5 points 3 months ago

Urgh, I go to sleep, wake up, read soooooo much awful wrongness.

Thanks for the vote of ~~confidence~~ fact.

[–] intensely_human@lemm.ee 3 points 3 months ago (3 children)

Nope. Purple is a wavelength that partially triggers both the red and blue cones.

The visual spectrum is continuous, not just three wavelengths corresponding to the three cones.

The blue cones and the red cones are stimulated by purple light. It’s a mix of blue and red signals from the retina, but the light is a single wavelength that is actually purple.

[–] stealth_cookies@lemmy.ca 12 points 3 months ago

No, purple is a non spectral colour meaning it is incorrect to call it "a wavelength" but rather you say it is a perception of multiple wavelengths. Not that this is special, pretty much everything you see is a non-spectral colour.

[–] AFKBRBChocolate@lemmy.world 10 points 3 months ago (1 children)
[–] LordWiggle@lemmy.world 2 points 3 months ago

This is the best in depth scientific explanation here, and deserves more upvotes. Thanks, was a nice read!

[–] Honytawk@lemmy.zip 4 points 3 months ago (1 children)

Purple is a green wavelength that doesn't trigger the green cones in your eyes.

It is made up by your brain.

[–] CerealKiller01@lemmy.world 1 points 3 months ago (1 children)

So what would be the color created by a wavelength of 550nm?

[–] feedum_sneedson@lemmy.world 3 points 3 months ago (1 children)
[–] CerealKiller01@lemmy.world 1 points 3 months ago (1 children)

Ohhh, I think I get it.

Purple is what you get when you force the visible light spectrum into a wheel, so there'll be something that "connects" blue with red?

If so, is the reason we perceive green as a different color than purple is because we have receptors for that specific wavelength, otherwise both colors would affect our red and blue color receptors similarly?

[–] feedum_sneedson@lemmy.world 3 points 3 months ago* (last edited 3 months ago) (1 children)

Essentially, yes. Although violet is a colour, and that does correspond to a wavelength of light. I'm not really sure where violet ends and purple begins.

Looks like this guy has had a crack at explaining the difference, though.

[–] CerealKiller01@lemmy.world 1 points 3 months ago
[–] Tolookah@discuss.tchncs.de 12 points 3 months ago (1 children)

Right, indigo is a color (~425nm), violet is a color (~400nm), purple is typically a blend of colors.

See more: https://www.sciencelearn.org.nz/resources/47-colours-of-light

[–] DarkDarkHouse@lemmy.sdf.org 9 points 3 months ago (1 children)

Fun fact: blends of colours are also colours.

[–] Tolookah@discuss.tchncs.de 8 points 3 months ago (1 children)

Nu uh!

Okay, poor choice of words by me. Wavelength color vs what the eyes see.

[–] DarkDarkHouse@lemmy.sdf.org 2 points 3 months ago

No worries, sorry for the snark. I find colour fascinating, like, when you dream of a purple dinosaur that's colour without any light at all.