Hi maclarencat, personally I wouldn't even think about painting the door. They are not made to be painted and the chances of it sticking are pretty slim. These doors are quite close fitting and putting extra layers on them wont help them to close properly and you could end up with problems that way. Only my opinion though. Good luck whatever you decide to do.
Thankyou. I did speak to a paint manufacturer before deciding to do this and I have been sold a base that will adhere to just about anything upvc included. the an undercoat then top coat. The door is white at the moment and I hate it but it is only 6months (Put in before we moved in) so I am going to risk it. If its successful great if not oops need a new door.