Dark Ceiling Can Make Space

On Rate My Space they are always painting the ceilings of every make-over they do. Why is that? Does it make the room look larger?

Colorman says:

The notion that a dark ceiling will 'drop' on you is a cliche. But it's not always true. Human perception is a funny thing. I, for one, have a rather small kitchen which I painted dark blue, almost black. The effect is that it makes the space look larger rather than smaller. The trick is that dark colors can make walls and ceilings disappear, rather than coming to the foreground. But it very much depends on how it is used. Here's a nice example of the use of dark color in a German underground station. See how the walls and ceiling seem to disappear?