Before 1939, German military equipment was painted in cloud patterns of 1/3 dark brown and 2/3 dark gray. From '39 to early '43, it switched to dark gray or dunkelgrau (your Panzer Black Gray). After early '43, dunkelgelb (Dark Yellow) superceded the dunkelgrau.
Given this your paint is applicable for any equipment that would have left the factories in the timeframe I cited.
The actual shade of dunkelgrau was very close to black. However in modelling, you may want to take into account “scale effect” the lightening of objects far away due to atmospheric haze. A 1/35 model 12 inches from you is supposed to represent something at least 35 feet away. It’s color intensity is lessened as your mind registers it. Therefore, many modellers lighten their projects depending on the scale to mimic this effect – to trick the mind into seeing what “looks right”.
Like Vartan, I wouldn’t get too stuck on the amount of shade or tint given the accumulation of dust on EVERYTHING.
In another vein however, I wouldn’t necessarily assume that there was wide variation on the factory issued paints. I’m stepping out on thin ice here I know. In regards to dark yellow at least, I’m inclined to believe there was little if any variation of the factory specs. Listening to restorers, collectors and historians, I recall one discussion where several pristine wartime items (by pristine I mean, never unboxed, never handled, practically mint). They were items such as a telescope tripod, the inside of a sealed spare 2cm barrel box, an unopened Notek blackout lamp and other misc equipment that somehow have weren’t issued and kept in near-mint conditions. These came from a variety of factories and were produced throughout the '43-'45 period. The restorers/collectors/historians concluded that there was NO discernable variation in the paint hue. Their logical conlcusion was that whatever controls for paint uniformity were widely held. Also German dunkelgelb is made from a base pigment of some sort metal oxide (I don’t remember which). This meant that, unlike synthetically formed pigments, it was already in its basic color and therefore would not react to bleaching by the sun. (Thomas Jentz seminar, AMPS Nationals '02)
For all that, what does that mean for modellers? Well, like I said, dust and weathering would affect everythhing so even if the theory that most likely every batch of dunkelgelb matched almost perfectly, it wouldn’t matter much in our attempts to model 1/35 scale replicas. Weathering, paint streaks, un-uniform paint application (thin spraying would have red primer show thru) would all affect our models.
So if your experience with mis-matched batches of paints counters this and you think my story sounds ridiculous. OK. That’s fine. It doesn’t affect the ultimate painting of our little plastic toys anyways.
My two and a half cents,
Roy