You can buy vinyl spray paint which you could use to convert a black one. If the door panels are faded too then you can freshen up the whole lot with the same colour. It works very well - use a solvent to clean the material up first and soften it prior to applying the paint.
This is not a great picture but shows the door panels, centre console, door pillars and handbrake gaiter that I sprayed. They are a different shade to the seats but I'm not bothered about that.