X77's used the standard no-ring bezels; NOS bezels (I have a couple, plus my originals), are Argent right out of the box.
I had to replace my original grille in 1977 due to a fender bender (no sheet metal damage, but those Audi taillights did a number on the plastic egg crate of the grille). The NOS replacement I bought was black by that time - superceded a couple of years before that, I imagine.
Regards,
Steve