the inner rim of my 214s came silver just like the face, but a few weeks in they became black... BRAKE DUST. I actually don't mind it looking like that as it is uniform. You're not going to be able to keep them silver unless you are meticulous about it, every week. I only clean what's visible on the outside and they still look great. Point is that the accented parts - if the inner rim is what you mean - will get dark regardless.

__________________
'08 X5 3.0si - Alpine White / Saddle Brown interior
Specs: Sport Pkg, Premium Pkg, Tech Pkg, Comfort Access, Aero Kit, Style 433 staggered 20s on Conti DWS
Mods: Carbon 35 tint, LED angel eyes, GP Thunder 7500k fogs, H&R 20mm/25mm spacers, clear reflectors, gunsmoke-tinted taillights
Coded: Digital speedo, windows/sunroof/tailgate close via keyfob

X5 pics at Flickr