If I recall correctly, the yellow pages was a hip way to refer to the entire telephone book, because it had yellow pages in it, and most other books did not have any yellow pages.
the phone book had 2 parts: the white pages, the front part, which was everyone, by default, and the yellow pages (the 2nd part), which cost money to put your business name in (with more money, you got a large ad with graphics)...you could pay $1 to keep your name out of the white pages...
