Jim your last query.
Following many tests by 23CG at Maxwell from Aug. 1 1940 ( Report 5-39-2) the Air Corps concluded that the best camouflage "under all conditions " was Olive Drab & Neutral Grey; the test results and recommendations were all included in Air Corps Board Study No. 42 "Shadow shading of airplanes", 27 July 1941. Permanent paints to be used rather than the pre-war water-based as listed in 1940, ie. OD41 for 31, NG43 for 32, Black 44 for 33.
They noted in the Study "that all airplanes regardless of paint color appear as silhouettes when viewed towards the sun". Also a dark green was best against a mainly green background ( Sea Green 28 later Medium Green 42).
Multi-colour schemes on US aircraft were mostly for exports to Britain though AAF Theatre Commanders had discretion.
This page is from Study 42 after 23CG tests in the field involving P-36, B-12, B-18, B-10, PB-2 and 2 School Sqns. Flight testing from August 39, from July 41 designated as Air Corps Proving Ground Det.".
Nick
report5-39-2 by
Nicholas King, on Flickr