KM c550 copies with background tinting

[Haberprinter]

purchased a used C550 and was copying great for about 50000 copies until the imaging units needed replaced. The tec tells me that he is using Konica supplies but a tec from another company told me if the drum is shiny it is aftermarket. My drums are shiny green and not the flat green like he said I should have. My questions are- 1. Do they even make aftermarket supplies for this machine? 2. if they do how can i tell if they are putting aftermarket supplies in my machine? 3. does it even make a difference? 4. Does this have anything to do with the background tinting(the sheet looks dirty after copying and has microscopic toner scattered all over the sheet). I have been using hammermill color copier stock.

Any help!
Thanks