hello, here is the answer from Mr thomas illming from the Heeresgeschichtliches Museum in wien.
I received your request for information about the colour of the ADGZ in the Austrian pre-Anschluss army.
I regret, but I have to tell you that it is not possible to give an exact description of their colour.
We know, that the tanks of the Austrian army were painted in several different colours at this point of time, obviously NOT as a result of a certain system, but depending upon which company had delivered the various tanks, and also upon the fact that various tank divisions were trying out different variations of camouflage at this period.
We know, that the “Kommando Schnelle Division” had started to paint their ADGZ from July 1937 on with a matt brown-green, which was defined to be similar to the colour of the last tranche of the CV-35.
Please note: the definition was not, to be “exactly like”, it was “similar to”. So we have to accept, that there was obviously no standardized colour “matt brown-green” in the Austrian Army at this time, and therefore it is impossible to define it now exactly.
About the rest of the ADGZ: I have not found evidence for their exact colour. It might be, that they had a – more or less - standardized colour, but it might also be, that they were, like those of the “Kommando Schnelle Division”, part of several programs running at this period for finding new colours for camouflage.
I hope that this response is nevertheless of some help for you.
Please do not hesitate to contact me again, if you have any further questions."
I was trying to contact him again but receive no aswer till now