That's curious; black's the only colour I thought that body shape and its predecessor never suited! But, I think the big Merc saloons look best in black.
I'm sort of partial to Merc silver, my wife hated it and thought it looked unpainted, and we had a friend with a champagne 500SL. I wasn't unhappy for him, but I think I'd have gone for something else - perhaps a very dark blue or a claret red. but red's a very difficult colour to get to suit different shapes. My little X1/9 was a sort of pale red/orange that sounds awful but actually looked rather nice. Shortly after I bought mine they introduced a black one called the Lido with white seats; it looked good, but the very best of them was a different red to the one I was able to buy, much more akin to the red used by Alfa, my next set of wheels. I don't like the current red Alfas I see around here - they look different, but it could be a trick of the memory
I've now had three black cars - two Fiestas and an XR3i. They do look good clean, but don't look clean for very long, as you point out.
Well, the gloss doesn't seem to last very long now either; for the first few months after I bought my current Fiesta it kept its gloss very well; now not so, even when just washed, as this evening. I think I've said this before, but I suspect it has something to do with the use of water-based paints which, by the way, also seem to have far less 'hardness' to them: I am very careful, yet there are lots of scratches around the door handles even though I never have to use a key! I really don't know what they thought they were gaining; perhaps it's cheaper.
Going past a hoarding today I noticed it saying that all Ford's models were offering 25%... I couldn't catch 25% of what, but it doesn't appear to say anything very positive about the state of the market here.