For a void to be 'absolutely nothing' it would have to be in a universe with absolutely nothing. You can not have a void when there is anything 'not void' around it.
If there was anything around the void, then it would be sending radiation of some sort through the void, and then the void would not be absolutely nothing. It would have something - the radiation going through it.
So either your void is contained in a universe that allows nothing in or out, or it can not be a void. That is, the void would have to be surrounded with some completely impervious 'membrane' that makes it, well, its own self-contained universe, with its own infinity in which there is, well, nothing, and which is surrounded by nothing, and that nothing goes on for infinity. As soon as you can 'see' anything, anywhere, in that void, even if it is on the 'outside', it is no longer a void.
So in that sense, you are perfectly entitled to have trouble with what this void would look like from the outside. There could be no 'outside' to a void since that 'outside' would result in something inside the void.
In that sense, since the void would have to be completely contained in its own universe, surrounded by a membrane which in fact does not constitute anything inside the void (you could not see the membrane from inside, there is nothing to see), you can make that membrane anything you want from the outside. You would not be looking into the void, you would be looking at the membrane, the boundary to the void. Make the membrane anything you want from he outside - invisible, opaque, red, a glowing orb, white, black, polka dots, camouflage, absolutely anything you want. It is not until you go through the membrane, or at least be part of it (sort of like putting your face right up to a bubble without actually bursting it - you see the outer surface of the bubble right up until you are part of the bubble) that you are in the void, and then you would see - nothing. Not even the way out. But then it would not be a void any more if you were in it.
But if you are interested in the human perception of nothingness, then research the ganzfeld.
‘Ganzfeld’ is a German word for a featureless field. The Ganzfeld
effect is a phenomenon where a person of normal sight is unable to see
anything after staring at any featureless, monochrome field for even a
few seconds. This is a normal response from the (human) brain when it
is starved of any stimuli.