Up to the battle of midway which shade of grey was early navy planes painted

[TimEwers]

And I'm talking about the underside color

Lt sea grey

flat gull grey

lt grey

or cammo grey

 

[Wayne Little]

As I understand it the lower surface was M-495 light Grey similar to FS36440, while the upper was M-485 Blue grey FS35189

 

[Wurger]

Yep... I agree. These were used for the two-tone camo scheme. The M-495 light Grey FS36440 can be the Humbrol 129, Gunze 325, Testors 1730.