Just watched all 35 parts and find it very interesting and useful. Has a new builder to ship's.

Regarding the color of the ceiling, i can't say much about the royal navy but i know that the ceilings on japanese and american warships were typically white or a very very light shade of grey. Probably for scattering the light and getting a generally brighter interior, the same reason why most walls and ceilings inside buildings are painted white. Since the japanese navy took a lot of influence from the royal navy and its just practical i assume they did the same. Warship models rarely have any detail for interiors and i doubt that ceiling will even be visible once its installed but its a nice bit of detail i came across and i thought i'd share.