In the 3rd episode of the 4th season of Episodes, Matt takes Beverly to a Golden Globe gift party. While entering it she says (writing from memory):
It's like being in Wizard of Oz. In colour.
Since she added "in colour" she must have been referring to the movie, not the book. What I don't understand is why she added it in the first place, since the most known 1939 adaptation is in fact in colour (and notable for its use of Technicolor) and all the later adaptations are obviously in colour as well.
I seriously doubt she meant any previous, black and white adaptations, because they were short animations, silent movies, etc.
What I think is most plausible is that when she was a kid she watched Wizard of Oz on a black and white TV and later watched it in colour and that's why she differentiates it like this (as if it were two different movies). I'm also thinking that this could be an English expression used to emphasise this kind of film-related analogies.
Could someone confirm my hypothesis or provide a different explanation?