Midway livery would be overall bluegray up top, light gray underneath.
The red/white rudder stripes were overpainted on USN/USMC aircraft between Coral Sea and Midway. Likewise the red dots were removed from the insignia (and in many instances the fuselage insignia were made freakishly huge).
I'd check out Yellow Wings Decals. Doubt they'll have exact markings, but they do a lot of early war USN insignia, squadron codes and the like that would probably be a big help.
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