[Pilot]

Oberst- green is in most cases based on chromium oxide green pigment then you have other options like black and yellow mix, black and ochre mix and as you say, blue and yellow. If you see any US Pacific airplanes you can note that dark blue can much fade out. As well there is cans found out, there is remained documents as well many relics, I am sure that in deep research can give full answer on colors. Did anybody try to do spectral analysis of the preserved paint samples?