Words, words.

Until recently, I never really understood the expression "the moon is made of green cheese".  Firstly the moon isn't green, and secondly do you know of any cheese that's green?  Blue, yes, but green?  So I felt a bit of a fool when it was explained to me the other day that green didn't refer to colour, but simply meant unripe - and of course young unripe cheese is creamy-white - like the moon.