Alternatively, you can polish them; I do this only annually (in Toledo, it was before the All Brit Show 1st wk of June, but down here, the All Brit show isn't until the last Saturday in October). I keep threatening to clear-coat them after polishing (PPG makes a urethane clear suitable for raw aluminum, it's what's on my engine-turned facia) but I never do.
I may have an extra set (for sure I have plenty of door trims!) so if you find a good vendor for anodizing, I may consider doing it too, though in comparison, it'll look dull after them being polished...
The trim kind of shows up in the picture below, though it may be smudged, as I had just fit the door cards and inner door trim.
High resolution image here:
https://spcarsplus.com/gallery3/var...e/Interior_Makeover/IMG_2995.jpg?m=1304277021
(may require a second click on the opened image, depending on your browser)