Regarding the original question, most are chrome. I've seen some polished aluminum ones but they eventually get tarnished, like this one.
Dear Gentlemen, dear fellow owners!
Please....!
Please, please don't get confused here.
The Pagoda SL has had a
chromed gas cap, only! Never, ever anything else.
Please see also our Wiki section on the lockable gas cap. The info is all in there.
Ooops, it was not! Edited it and added the missing info .In summary:
A000 471 2030 gas cap from YMOS; all chromed, non-vented, ones-sided key, up to 280 SL #010355
and
A000 471 4730 gas cap from YMOS; all chromed, non-vented, double-sided key, 280 SL only from '010356 onwards.
Enjoy!
Achim(chromedgascapcollector)