I think my natural tendency is to shoot Street images in Black and White. Probably because in my brain colour can often conflict with what I’m trying to achieve. For me B&W has a more graphic quality that is very direct. Having said that I guess it all depends on how one sees the subject and what you’re trying to achieve.
The above image is certainly a strong and obvious candidate for colour treatment and importantly one that is much weaker in monochrome.
Technically speaking many cameras allow the photographer to capture an image in two different formats such as JPEG and RAW simultaneously and often with the JPEG adopting a film simulation profile. I often shoot with a B&W JPEG profile such as ACROS as well as a RAW file. This obviously means that I have the versatility of great B&W film simulations and high quality colour backups. You can enjoy the best of both worlds.