what is more popular silver or black face plates

I think certain gear looks better with a black faceplate and others silver. I personally don't care that much my gear is a mix.

I've had systems that were both although I've had black more often.  My current main system, which I believe will be my forever system, is black with the exception of the isolation transformer which was a carryover from previous system configurations, although I'll likely swap its silver faceplate for a black one soon.  All-in-all I prefer black.

Usually black, but ARC gear looks more "right" in natural aluminum (silver). Atma-Sphere’s champagne is my all-time favorite.

Undecided…

The 70’s silver face units were, in my mind, the bomb.
 

Nowadays I prefer the black face units as they can be swapped out without much heat from she who must be obeyed.