The problem is, there are many films made today where the colour is not really necessary, but you don't have a choice because the distributor wants colour so he can sell it. But I always have a kind of "thinking exercise" with the director, "Why not in B&W?" or "Why not in colour?" So if we explain it to ourselves we know where we have to pay attention because if you make the kind of films I generally make colour could give you too much information.
http://moviexpress.tripod.com/id9.htm
http://theartofmemory.blogspot.com/2007/03/robby-mller-cinematographer.html
http://www.youtube.com/watch?v=NDLd2rULl3A
http://www.youtube.com/watch?v=5jEfuqAMCa4
http://en.wikipedia.org/wiki/Robby_M%C3%BCller