You have three basic options, live with it, paint it or replace the door panel. I've always thought our 09 interior was more charcoal grey than black.
You can go with Duplicolor interior
Dupli-Color :: Vinyl & Fabric Coating
SEM Products :: Home
Both products say the same basic thing. Clean, clean, and clean again (wax and grease remover to eliminate fisheye), then spray with an adhesion promoter followed by the color top coat.
Only other option I see is having the door recovered or a interior carpet kick panel made by an interior specialist. The few mars and scruffs on mine come from entering and exiting the car.