I've been pretty busy with commercial installations during the last few weeks, i.e. prints for offices, condos, buildings etc. and although I've been posting a lot of photographs, I haven't had a chance to go through the logic - if there is any - of what I've been doing as far as color / digital / b&W and all that stuff that just takes too much energy to put into words.
But let me try anyway. These are rules, more or less, about what works for me. But your results as they say - and the results I've seen for other photographers - definitely may vary.
If I'm dealing with street shots (and by that I mean those odd-angled, quick shots where
strangers are prominent, and the picture has to do with confluence of human beings in the moment) then black & white works better.
Some of this may just be historical - what I'm used to looking at - but some of it may be because we (and I speak here for the human race in general) want to see ordinary things - but only if they are abstract and black and white does that. Abstraction distances the viewer so that the ordinary can be seen as "art."
The blurry guy jumping across the puddle by the railway station works in b&w because it is more abstract then if color had been used; who knows if color might distract from the concept of the picture; and even the blur helps to make this an "everyman."
There are exceptions to the "street b&w" rule - where color has either been made to play a part in the street image - or is actually important in the shot - but again - these are exceptions. Again - I want to place emphasis on the proportion and the importance of the people in the shot. I'm not talking about tiny people in the audience or on the street.
City Landscapes. Again - there may be people in the shot - but they're not that prominent. Now here I think you've got more choices. If the color is either more or less "real" - i.e. more pictorial, then how we actually see color - then you can distance the viewer so that they feel that it is easier to achieve an aesthetic feeling. But the same could be said for black and white. So the urban landscape is a toss up.
It's a tricky business. We say that we want to see ordinary things - but want we really hunger for - is ordinary things - seen in an unusual way.
Sunset is popular because the atmospheric effects are recognizable - but rare. If the entire day was sunset, and there was only 1/2 hour when the sun was bright, glaring and glaring down at you - would that 1/2 hour be the most beautiful time of day?
How boring would it be to always be looking at an orange sky?
In other words - as far as color goes - the subject matter can be banal: a doorway, a fire hydrant, a building - but intensified color or black and white can give an air of abstraction that allows the viewer to see the form as if for the first time. And the reason that this is a little bit easier for the artist to achieve - as opposed to shots that are more "of the moment" is simply that there is more time to contemplate how the pieces fit together in terms of color and/or black and white whereas to get the pieces to work on various levels with the "quick shot" seems to be nearly impossible for me. And I say "for me" because I have seen this trick accomplished.
And if you can do it - more power to you.