I just bought brand new rotors for my front wheels last week. I noticed that before I had the new ones installed that the outer lip of the rotors were rusted. After installing the new rotors and washing my car the outer lip has changed from a stainless steel color that matches the rest of the rotor to a dingy gold color. I believe this is from either the tire degreaser or wax that I use at the car wash getting on the rotors. It turns the whole rotor this gold color but after a few minutes of driving on the road the part of the rotor that makes contact with the brake pad becomes its normal stainless steel color again (I guess because the pad wears off the corrosion). I am wondering if there are any solvents or cleaners that can make this dingy gold turn a silver color again. I tried paint thinner and it helped a little. I am wondering if brake fluid or something else would do the trick. Thanks for your help.