First off, decks were painted acording to camoflage appicable to each navy. Most USN ships used Weathered Deck Blue, but there were variations. I would research the applicable instructions for the ship you are building.
as for lights, from what I have read, lights were not shown during wartime except, perhaps, in harbor, and even tha was questionable, ie Royal Oak. It was generally, ecept along the US coast in 41' and 42', considered to be asking for a torpedo, to be showing ANY kind of lights on a ship, even cigarette butt glows.
All that said, it is, again, a case of researching the applicable regulations relative to your Navy's ship. I woud suspect that the Imperial war Museum or peraps the RN's museum would have the answer for you.
Sorry to be round about, but sometimes it isn't really clear.