This is actually a valid comment. Black/white in black/whitelist has to do with something being illuminated rather than with the color. Same with the dark web.

opaque web? obscure web? cloaked web?

There is a rationale for different terminology here, other than race-related. Tor is encouraging more 'regular folks' to become users, rather than mostly usual suspects such as journalists, activists, opsec etc. But the connotation of dark web is too much related to sinister / criminal / illegal / dangerous (and yes there is a lot of that too).

Dark matter could be renamed to invisible matter. And before we know it we can't say anything.