Re the black spray paint? Not sure what brand...got it at Lowes Hdw.
Technically you are correct about the aluminum but in this case, 90%
of the surface was nicely bonded factory paint so you are actually
coating the paint. The scratched areas you can go over with a light
coat of alum primer. I didnt bother and its doing fine.

 

You all have had trouble with paint adhering to bare aluminum? I only have that problem if it's really smooth or not clean enough, but even then it's not usually a problem.

I picked up some cheap paint sprayers today, so I'll do a sidecover color-match experiment or two in the near future. Maybe even a writeup will follow if someone doesn't beat me to it.