Chipping Panzer Grau: What Color is Underneath?

.  Scuff...don't chip...

My opinion only. Don't do it. I think German dk grey vehicles chipped to expose red primer is vastly overdone. I prefer to show a dusty vehicle with darker clean areas where the dust is removed by the crews hands, feet and uniform and scuffling w/ underbrush

An educated guess says primer, then steel. Since the Germans used a primer red on portions of the interior such as the engine compartment, that is a possibility. Again, this is only an educated guess.