radartec65
Also do you have the FS # for the Standard Deck Navy Gray #20 ?
In WWII The Navy Department used the Munsel Color Reference system. Many of the USN ship colors were in the "Purple-Blue" range of that system.
The Federal Standard color system would not come about until abotu 1954, with Department of Defense adoption circa 1955, supplanting the A/N (Army-Navy) color standards left over from 1946.
There's a good, if very old, thread by EdGrune on this here:
https://cs.finescale.com/fsm/modeling_subjects/f/7/t/129857.aspx
This link suggests https://www.internetmodeler.com/2003/august/ships/color_part_1a.htm
FS37030 as equal to Deck Gray 20G, but it's also rather an old link. So, a gain of salt will be wanted.
Many USN ships in WWII used a "slime stripe" of darck greay or near black 6-8 inches (15-18cm) up from the deck on vertical bulkheads to keepthem from discoloring dues to sawhing and the like Accedotally, used of a brick red has been reported on USN carrier hangar decks.
Either would have also been subject to individual Captain's discretion, too--so you want refence photos to make your case.
Hangar spaces are dark by nature, even when filled with artificual light. This can make photographs complicated to interpret, especially B&W ones developed for "full saturation" (e.g., every tone of gray from pure white to pure black in the photo).