Hiya guys! Chris Coulter seems to provide a clue to this which I think is rather feasible. He link me to this website & said the following:-
http://homepage1.nifty.com/watakan/yamato/research/color_general1.html#new_color_reserch
which talks about Yamato's deck color, through the altavista babelfish translator at http://babelfish.altavista.com/, and it mentioned that natural wooden decks of the same type of wood as Yamato, turn gray after several months from being in the sun and with exposure to the elements. There is a few picture at the bottom of the link of another ship which shows the color variation from the natural color to gray. I can't say how accurate the site is, but he has a lot of intersting info about ijn colors and Yamato in general and seems very, very passionate about the subject."
It seems quite logical to me. The colour of the deck in the pic sure looks like paintwork(though it is not)after some exposure under elements. If what Bob LaPadura said is true about the oil swab, it should give of some semi-gloss reflection liken to paint work, which give rise to what Russel Spurr said about the grey camo paint. This is the most plausible answer for the moment. Then the next question is, why swab oil on the deck? Isn't it gonna make the deck more flammable? Or is it the other way round making it inflammable which will coincide with what Spurr said again about inflammable paint. Jeff, Bob, I think I need you guys to enlighten me on this. Much thanks.