what is more popular silver or black face plates

The last two pieces of electronic gear I upgraded were based on the deal I got, and one had a black face plate (the SA 10) and the other had a silver face plate (the SLP 05) so for me it is more about the price of the gear that I want than the color of the face plate or chassis, but if price was not my consideration and I was ordering one I would choose silver.

Its more important that the equipment work than look good.

That would be my first consideration as well, followed by the price for which I could get what I wanted.  Face plate color would be way down low on my list of priorities.  But I honestly do like silver or probably almost anything, as far as the looks department, better than the standard black box.  But I will buy the black box in a heart beat if it is the one I want and the price is right!