YP is the most overated advertising there is as far as I am concerned.
I spent £2K this year, and what a waste of money!!!
I had a mouthy rep come round to tell me what I need who didn't have a clue. The 118 247 is "THE" biggest waste of money in the History of advertising ( I advise everyone to stay away from this) plus the web advert which I have the big one for 3 years now is also a complete waste of time.
I get more decent work out of Parish Mags. at a fraction of the cost than YP, all I can say is thank God for recommendations and repeat business because dont rely on YP.
As for colour v Yellow/Black I agree with Shaun YP will tell you it makes all the difference, well it dosen't, spend the same money on an advert twice as big in Y/B if your going to go in it.