I'm not really understanding this gray gets dirty easily thing.

I have an X3 with gray leather and aluminium trim. The leather looks new and it doesn't show dirt easily. And by dirt, I mean the occasional "light dirt from my mountain bike tyres", since sometimes it contacts the interior door panel or the front headrest. After 5 years, looks brand new. It would shame the interiors on most CPO cars.

My mother has a 325i with Black leather. That shows dirt so easily, along with sun creme, lotion, and the "gravel dust" from shoes when one parks in a gravel lot. I've warned my mother to avoid using lotions and cremes since it rubs off on the side panels and armrests, but it's like I'm constantly scrubbing it off. It's a good thing it ain't my car.