My understanding is that blind people don't see black or any other colour, they just...don't see. I've seen it described as "what colour do you see behind you when you look straight ahead?"

That said, probably just black I guess, if I had to choose.

Translucent neon clear with a hint of purpular pastel.

Cheese answer: a live video display of what's in front of me.

Real answer: black/white gradient blobs representing light and darkness in my surroundings.

Funny answer: bouncing DVD logo

Doesn't matter as I would be blind and couldn't see it.

Eigengrau. It's what the brain fills in anyway when there's no visual input, so it wouldn't be a distraction if that's all I could see.

I'd have plenty of extra problems, but that, at least, ought not be one of them.

Octarine

A dark grey.

Problem with going blind is that you can’t close your eyes and see darkness anymore. Dark grey is super boring, but it would allow me to sleep reasonably well.

Probably a warm colour like the shade of red you see wghen closing your eyes while facing a lightsource

Hooloovoo

Purple

I am not sure the question makes sense, but I'd like the daytime to feel "lighter" than the night. As though I still had some sort of visual perception.

I would also love to learn to echolocate.

For me I think I’d prefer a lighter colour, maybe something akin to a fog with some varieties in the consistency of it so it doesn’t feel like a solid wall of grey-white.