"Black rims" refers to the color of the wheel rims on a vehicle. It means that the rims are painted or finished in black color instead of any other color. Full definition
There's also thin black buttons on either side that blend in ever - so - nicely with everything else — like a black car with black rims. (androidcentral.com)
They are so cute, I love the little black rim on them. (theinspiredroom.net)
Complete with a set of custom 21 inch black rims with a nice polished lip. (topspeed.com)