this post was submitted on 19 Jul 2024
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[–] [email protected] 33 points 1 month 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.

[–] [email protected] 26 points 1 month ago* (last edited 1 month 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 12 points 1 month 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.

[–] [email protected] 6 points 1 month ago

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

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

[–] CerealKiller01 1 points 1 month ago (1 children)

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

[–] feedum_sneedson 4 points 1 month ago (1 children)
[–] CerealKiller01 1 points 1 month 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 3 points 1 month ago* (last edited 1 month 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 1 points 1 month ago
[–] [email protected] 0 points 1 month 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.

[–] [email protected] 13 points 1 month 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 11 points 1 month ago (1 children)
[–] LordWiggle 2 points 1 month ago

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

[–] [email protected] 2 points 1 month 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.

[–] [email protected] 13 points 1 month 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

[–] [email protected] 8 points 1 month ago (1 children)

Fun fact: blends of colours are also colours.

[–] [email protected] 8 points 1 month ago (1 children)

Nu uh!

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

[–] [email protected] 2 points 1 month 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.