Hi! sometimes you have to be careful judging the colour of the oil as often garages do not empty via the drain plug preferring to suck the oil out through the dip stick. This method does not get all of the old oil out as you would with emptying at the sump plug. The old oil discolours the new oil fairly quickly, I found this out by arguing with my dealer when the car was in warranty and they were doing the service, I always checked afterwards and once complained that they had missed changing the oil it was quite dark......As always the only way you know exactly how and what was done is to do it for yourself........
Always said I would go back to a 6 series