Unsolved Rims colour

I just wondered how to do a simple mod of changing the rim colour on an official rim without over writing it and adding it as an option in the parts configurator

 

You can make a copy of the rim you want to modify and make a new part with it, using the alternative diffuseMap/diffuseColor.

Like, I made some alternative polished steel rims as a new part by editing the stock 13x5 white ones.

 

Ok thanks, but where can I find the rim and the corresponding texture

 

All stock wheels are stored in a zip file in your game folder (/BeamNG.drive/content/vehicles/common.zip).

The archive contains subfolders, rims are in /vehicles/common/wheels/.