Black Sea Sub Colors

Anybody have info on the color used on Black Sea Soviet SHCH class subs? Working on the Zvezda kit. Their info shows a pale green color for 1940. One reference I found says , like tanks and 4BO, you can choose any color as long as it is “flint” grey. (whatever that may be) I can see the logic of the pale green. I read somewhere that one Navy figured out the black / dark grey in vouge at the time actually made it easier for an aircraft to spot a submerged sub down to 100 feet or so. (big black silhouette under the surface) I am aiming for a 1943 time frame, to go with a U-20 kit.

Was checking the kit instructions and noticed they say Tamiya XF-65 Field Grey. (I swear I saw a mix of two colors from Humbrol or something else not readily available in the US.) Supposedly Vallejo 70.890 is a match. This sound 'bout right?