... I don't believe her wood decks were painted in 1941, but if you have ever seen a salt stained teak deck then you know how grey in colour they can get. ...
IF it works, this gives some of Rodneys photos from the IWM (you could also try searching on Nelson).
Alan Raven (and others) stated that at the "start" (?) of the war many ships' decks were stained with fuel oil (to the horror of first liutenant and relief of the matelots). This photo shows the job being done - note the sailors hands ;