The wheels on my 08 are aluminum, but they have a silver powder coating on them, as does most of the other aluminum parts (grab rails,swingarm, hub, and foot peg BRACKETS),
the folding pegs themselves are raw aluminum.... I think the forks are a clear anodized, with clear paint over.
I just did a quick walk around testing various parts with a "scratch test"
While I recall reading "do not use on aluminum" on a bottle of Simple Green a couple years ago, it does not appear on the new bottle I have...
but it does state: "DO NOT USE ON plastic instument panels, opals, or Pearls....." it has a high Phosphous content...
I had an instance when using it on raw aluminum cast surfaces where it began to turn "black-ish", and after rinsing had to scrub with a scotchbrite pad to remove the discoloration.
as they say on the bottle...."do a test on materials in question"
409 and Fantastic still bear cautionary statements...
anyways, any stone chips or scratches in the painted surfaces will allow the substrate to come under attack, and will progress the reaction at that site over time, corrosion will occurr...
just sayin....