Be interested to see a link to black ones you mentioned.

Random selection off Google: https://www.overstock.com/Home-Garden/Genesis-Smooth-Pro-Bla...

Are those just black tiles or are they black noise reduction tiles? I don't see any indication of the later. Is vinyl a common material for noise reduction?

Googling "black acoustic tiles" finds plenty of options. Any drop ceiling (https://en.wikipedia.org/wiki/Acoustic_ceiling) is going to dampen sound pretty significantly versus exposed metal/wood/concrete. You can also go pricier and get stuff specifically designed for sound studios, if you prefer (in quite a few colors): https://acousticalsolutions.com/product/alphasorb-quick-ship...

I bet the looks-like-tin-ceiling acoustic tile costs more than the white hospital-style stuff.

Probably! (Probably not that much more, though.) But so do comfortable chairs, nice tablecloths, and good ingredients. (And the reclaimed wood and industrial fixtures everyone's using...)