General agreement is just that, a medium gray.
Now, there are those who will suggest Deck Gray, and many contemporary photos certainly are that dark. Now, those photos are also coping with the contrast of the flat white interior bulkhead and overhead paint, too. So your mileage may vary.
Deck Blue is supposed to be on the decks to the outboard faces of the bulkheads and hangar doors. Supposed to be. Not a lot of photographs to point either way (and the Deck Gray is going to be as dark as Deck Blue in b/w photographs).
Mind, per the painting regulations, places in "permament shadow" like the undersides of overhanging deck elements, were meant to be painted white, to "countershade" them. About zero photographs depicting that, though. (Which is still odd for ships in Measures 11 or 21 the two Overall Blue schemes.)