Mayor- Amazing images. I agree with the others that the black and white brings cohesiveness and also allows you to see more of the subject /composition in a way by not distracting with the bright colors. However, I really like them in color as well.
I really learned a lot just now by your answer about how you ask peoples permission. I can relate about worrying if they care and thinking about it too much. I also have experienced losing what you were going for by them being to aware of you and posing too much. The idea of multiple pictures never really occurred to me for some reason. But that is a major tip.