Here's a color video of SS Hannibal Victory in 1944 ish. About 5 minutes in there is a view of part of the main deck that appears to be B 20. There are some other shots where the deck is visible later in the video.
The ship appears to be a medium grey with a bluish tint. Maybe Haze Grey? Or maybe color shift in the film? There is also a Part 2 of this film.
Hope this helps, David


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