Black and white street photography is often considered more artistic than color photography, and photographers who want their work to be taken seriously, often favour monochrome over color.
Historically, some of the biggest names have shot in black and white, people such as Henri Cartier-Bresson and Robert Doisneau but especially Eugene Atget, a Parisian who photographed life in streets of Paris in the late 19th and early 20th centuries.
Few of his photographs included people and instead his main subject matter was buildings and architectural details. He wasn't the first photographer to work on the streets but his output was prodigious and he is credited with being the father of street photography.
Above: Candy Floss Girl
Of course, all of them at that time worked in black and white. So there is a long legacy of great names attached to this method of working but that's not the only reason for choosing black and white street photography over color. The other reason is that for some shots, black and white works better in that it helps to unifying the picture plane.
By that I mean that removing colors which stand out strongly such as bright red for example, or that conflict with one another such as purple and orange, you can create a greater sense of harmony within the picture frame.
In the shot above, the candy floss was a very strong pink which I actually really liked but the bright red of the boy's T-shirt was stronger and jumped forward too much in the picture. Converting to black and white helped to unify the background and foreground. This was especially important as the depth-of-field was not as deep as I would have liked it to be. The aperture was f/4.5 - a bit too wide but it was an evening shot and the light was low. I set the ISO to 400 but could have done with it a stop or two higher.
So... excuses, excuses! The result was that the boy was slightly out of focus. Converting to black and white and sharpening the areas around the boy's head have combined nicely and the composition has gelled.
Overall, it's an amusing shot and I am happy with the conversion. So my advice is to shoot in RAW if possible but set your camera to black and white so that you can see what is happening on the screen while retaining all the information for conversion (or not) when you get back home. That way you can get a good idea of the finished result while always retaining choice.
Follow this link for more tips on black and white street photography.