It depends on the theater and lighting of that particular part of the world....
Sometimes it will be a dull grey gray.... or sometimes it will be a light light white greyish...
if in Middle east...
dude don't worry about the color, just worry about it looking realistic
I had a friend from Texas who served on a carrier deck who said that he went through a pair of boots every 2 days, because of the heat.... they melted to the deck..... plus... i have seen pictures of the pyramids in egypt ok, now imagine this on a FLAT deck
beautiful sun going down, nice REDISH pinkish deck....