"US ARMY" underwing stencil color

[warhawk]

I read that the "US ARMY" underwing stencil (applied to early war P-39 and -40s) color
was actually INSIGNIA BLUE, not black

Is this really true, and can it be confirmed with color photos?

[Vince_M]

I saw the wings of the p38 glacier girl during rebuild in Kentucky.  It was hard to tell due to oxidation but I'm pretty sure it was a very dark flat blue.

[warhawk]

So i have thought, thanks for the info 

[P-40 Admin]

Yep, blue 

[Buckeye30]

Air Corps Spec. 24114 (Oct. 22 1940 ) approved Insignia Blue ....
" E.4a. The marking U.S.ARMY on the undersurface of the wing shall be applied with blue, Shade 47 of Bulletin 41 ."  This was ANA605 Insignia Blue in Bulletin 157 ( 28 Sept. 1943).
The marking was ordered removed from May 29 1942 and from training aircraft Oct. 19 1942. Obviously all lettering was not deleted immediately but aircraft in production were no longer required to have it applied.
It would be difficult if not impossible to tell from photos ( even colour ones) whether some planes had black instead, no doubt that colour was used for convenience in some situations.
Nick