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.
what is more popular silver or black face plates
It seemed back in the 80's & 90's most high end components were black. Although some components today still offer black finishes it seems silver is now more popular. What are your thoughts & color preference?