Mi initial preference years ago was chrome, as Doug said, they just looked 'more mechanical'.
Later I got my worn Minolta SRT 303 (they only had one used body and it was black), things began to change...
Long after that, my first chrome camera and RF too, the Fed-2 with the aluminium Industar.
First 'assignment' with the fed, a wedding, Sevilla, mid July, 2pm, chapel's courtyard, straight sun over me and my fed. Arg ! sun strikes the aluminium barrel so hard I can't even read the f stop settings ! I am half blinded.
Mental note #1: Better get black lenses. Try to get graduated sunglasses as well.
Yesterday evening, Barcelona University central building, the legendary orange tree courtyard. Fed-2 w/J-8. Shooting candids with the fed in my hand.
Eyes looking at my hand, 'what's that bright thing ? oh, it's a camera! let's run away !!!'.
Mental Note #2: That didn't happen with my black Kiev. Better get black bodies.
Mental Note #3: The fed shutter's loud 'GKKLEP!' makes heads turn to me. Better don't use it in quiet places for candid shots.
Obviously half kidding
, but the anecdotes are real. Reality is that I like both chrome and black cameras, mainly if we talk about classic ones, which were mostly chrome finished. However, black tends to be more discrete for street shooting, as Peter's photo 'Suspicious looks' clearly shows