Do you remember watching the movies/series, before the tide of expanded material in books and magazines and then obviously the internet, and guessing things about the tech or character actions which you learnt aterwards it was not the intent of the designers/moviemakers? layout of the ship, for example.
Me first: In the movie Enterprise (also known as "refit", "Enterprise class", "NCC-1701-A", whichever you prefer), I remember seeing those big windows in the cigar section with bright blue light coming out and being absolutely sure that was the Engineering room, where Scotty had tha big luminous blue reactor. I even concluded the windows had shutters because of the inside scenes. But the blue light was definitely the reactor.
Then I bought Shane Johnson's book and "learned" that was "really" a botanical garden.
( Why a garden would be colored/lighted blue instead of, say, green, I cant guess