Started cleaning an old leather jacket and it started turning a lighter brown from dark brown. I stopped because I thought maybe I was removing the patina. The jacket has wrinkles and the dirt oil and grime are in the wrinkles making the wrinkles stand out. This may or may not be a good thing. I'm wondering how people treat there old jackets here. Is the grime bad for the jacket over the long run? I'm thinking they might embed into the wrinkles causing those areas do decay faster than they should. I was using a leather conditioner/cleaner.