I recall a Marx Brothers film where Groucho make a comment about Technicolor being so expensive. To me, Film Noir means a plot in which the good and the bad are not so cut and dried, so to speak. But some black and white films do not have a dark feel at all, and that's intentional, even though parts may be indoor locations. Outdoor locations are never quite the sunny places they would be in color (or real life) and probably work less well than indoor locations but that's just my impression. Some films in color still manage to have a Film Noir feel, just don't ask me to name one. I actually like some of the brilliantly lit indoor scenes of color films and it seems like a lot of movies from the 1950s and 1960s had scenes like that. Not all of them, of course, but they didn't have dark rooms and nighttime scenes. The movie that I think had the best light and darkness contrasts was (or is) The Third Man, which had some unusual low-angle shots with some tricks to make things reflect light.