On the question of the early-war 2-tone scheme in place from Nov '38 to June '40, that information is clearly contained in Panzer Tracts 1-1. They don’t repeat it again in other volumes of the series due to the varying print dates and other factors. So you won’t see it stated multiple times and the only place it appears is in 1-1 and includes a rarity in the PT series, actual color illustrations of the Dunkelgrau and Dunkelbraun colors prescribed for the 2-tone scheme. Jentz and Doyle support their claims on 2-tone via the use of original/primary source documents for the ordered schemes. The monotone Panzer Gray scheme was not ordered until June '40 and prior to the two-tone scheme, the ordered scheme was 3-tone, so there’s no factual evidence to support a monotone Panzer Gray scheme in place for the early WW2 campaigns. The two-tone scheme was applied at the factory or depot level with supplemental instructions that vehicles in the field with the prior three-tone scheme be re-painted as time/materials allowed to conform with the new scheme. That didn’t happen universally and by the outbreak of war with Poland, there were still units with gear in the older three-tone scheme.
As for photos showing the two-tone scheme, they exist in both b/w and color. Here are a few examples (taken from a wide variety of sources so not limited to just Messrs Jentz and Doyle in terms of supporting evidence) [;)] Notice that these pics are of clean vehicles in the b/w pictures and how hard it is to distinguish the two colors…once you get a nice layer of dust involved, even in the color pic on the Pz II it’s extremely hard to pick them out without looking at the pic in high-res and large dimensions.
