Join Date: Nov 2016
Location: Düsseldorf, Germany
I had more than 20 different 6C 2500 passing through our workshop over the past 10 years, but I am still not sure when the colour of the chassis parts switched from grey to black. Judging from the unrestored cars I have seen, I guess it was somewhere between late 1947 and 1948, but I might be wrong. Many restored cars from a later production date have now grey chassis, just because it looks cleaner and friendlier, but the cars I have seen in unrestored condition were mostly black underneath with a grey engine bay. I tried to find chassis parts on the grey cars which had not been exposed to sunlight (like attaching parts where something was bolted on) and tried to find an exact matching colour. I turned out that the type of grey varied quite a lot, with the green hue being more or less dominant from car to car. I have a feeling that back then they were just changing the shade of the colour when the bucket was empty...
After comparing with other cars and simply judging from a personal taste of what looks right, I would say that RAL 7033 "Zementgrau" is a very attractive match. I is a sort of green-grey, just lively enough not to look dull. And, furthermore, since it has been used on many restorations, it has become original now...;-)
But maybe someone else can join in and give a more substantiated opinion. Mine just comes from what I could take from restoration projects. Someone else might possibly have access to some factory records.