To expand on your idea, imagine painting an anechoic chamber with vantablack.

That's vantablack. A material designed to be the blackest, most light-sucking thing out there (artificially made at least). Essentially a forest of black nanotubes catches nearly all light and forces it to bounce around until dissipating to nothing.

I don't know what they'll use it for, but there are probably many uses. And if all else fails it makes pretty cool paint.