To me this is very confusing, but I hope we can discuss it and find a solid answer to the question.
If you were somewhere where there was absolutely nothing, what colour would your eyes see?
Black. If there was nothing, there would be no light, and nothing to emit light, so you would see no light. Your eyes interpret the absence of light as blackness.
Nathanial is correct, but it is important to note the phrase "...your eyes interperet..." The blackness perceived is a physiological effect, not the actual color of nothing as it were. I have a visually impaired brother and the best description I've ever heard of being blind is
"Blindness is not like what you see when you have your eyes shut or when you try to see in the dark, blindness is what you see when you try to see through the palm of your hand."
The fact is, sight as it is experienced, including the perception of color, is an incredibly individual experience. There are a number of species that see very different ranges of the electromagnetic spectrum. Butterflies, for example, see UV light; the pretty patterns we see on flower that we imagine attract polinators, actually look quite different to them.
The sonar that bats use functions in the same way as vision for most animals. It is very likely that a bat (to some extent) perceives their sonar in the same way we perceive sight. There is an excellent description of this in Dawkins' The Selfish Gene.
Black is a color defined by the absence of light. In additive color mixing (light), black is zero visible light. In subtractive color mixing (pigments, filters), black is a pigment or combination that reflects or refracts zero light. So, I think that's your answer; if there were absolutely zero EM spectra, you would call it "black".
However, you would call an environment rich in gamma rays, or infrared, or even ultraviolet, but with zero visible light, "black" as well; your eyes don't see any of those outer spectra and so you, with just your eyes, would not be able to detect that they exist (though you'd feel the heat radiating onto you, and you'd keel over from radiation poisoning quickly enough in a high-gamma or even high-ultraviolet environment). But, we have instruments that can detect these things, and either show you on a meter, or convert them to visible light so you can see them as if they were visible light. These instruments, in a space devoid of any EM spectra, would show you nothing; black.
Most people say black, becouse they think nothing is the same as closing your eyes or turn out the light. I think if you will step into a room with "nothing" in it, your brain will randomly create a collor. Or you see nothing. But can you see "nothing"? We don't or i don't know becouse we never experienced to see "nothing" noboddy do.
So the eyes are a body part, same with your ears, what is nothing? Just no sound or can you hear your brain waves?? We dont know. What if your eyes are removed from the body and your brain. What will you see? We can't think about it becouse it can be different by me.. Mabe i will see red and you will see purple.. Mabe you will see some of brain waves.... Nooo!!! You can't! If you have no eyes and you start seeing your brain waves ir a collor like blue.. What couses that you 'SEE' it? You can"t 'SEE'! Or do you have a eyeball in your brain that is looking at your brains blood and stuff!? No... Mabe you will see into an other world... Like the spirit world??? We don't know, i am now just making examples of what happens...
Mabe if some one asks "what do you see?" Then the eyeless human answers "i dont't know...." Or "i can not explain it". Mabe he sees something but he do not know what he sees exactly.. Hims brain can not tell him what it is.. Thats becouse consciousness.. Your consciousness can't image it.. So yeah.. Your turn to think about absolutely "NOTHING" heh?
We can't. And if you try... You will see a black collor or something else... But how can you "SEE" that?
No matter for how long you think about it.. You just can't
Good luck to "see" nothing. XD
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