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The Reverse of how colors work: how would it look?

Posted: Sat Mar 18, 2017 5:42 pm UTC
by WorldTradeRichard
It's a simple question:
Image

Upon looking at this drawing, I began to wonder what the object in Our universe (colored red when it absorbs all wavelengths of visible light except for red), would look like instead if it absorbed ONLY red and reflected all other colors, like an opposite. Moreover, what would an object look like if it's color was a solid "all colors except for red"? Does it just blend?

I understand slightly the answer, but I can't really put it into words and I have to explain it to a Younger one.

Re: The Reverse of how colors work: how would it look?

Posted: Sat Mar 18, 2017 5:58 pm UTC
by Sizik
If it absorbed red and reflected all other colors, it would look cyan.

Re: The Reverse of how colors work: how would it look?

Posted: Sat Mar 18, 2017 5:58 pm UTC
by Soupspoon
In the setup you have above, assuming specific red rays, green rays and DVDs blue rays, a red-absorbing object would reflect green and blue, which would result it in being seen as cyan.

But that assumes a rather specific lighting. Natural lighting is a spread of frequencies, with gaps that you don't notice unless you're looking for them. i.e. an object that was 'red' in that it absorbed only the red light at (say) 680nm, though, does it not absorb light at 640nm (still red)? 660nm (a closer red)? 670nm? 679nm? Given a white light source, the narrower the absorption, the more red-but-not-exactly-as-red light there is that still reflects to work with the reflected non-reds to appear "white" (or nearly so) to the Mark I Eyeball.

See https://en.wikipedia.org/wiki/RGB_color ... n_and_blue for the whole "why RGB"/vision thing...

Re: The Reverse of how colors work: how would it look?

Posted: Mon Mar 20, 2017 2:24 am UTC
by Eebster the Great
The "red object" in your drawing looks magenta to me.