I have seen many examples of selective colouring on Flickr. This is a process where the main subject of a photograph is left in colour, while the background is black and white.
I must admit, I didn’t take the following picture with the idea of processing it as a selective colour image. However, when I viewed the photograph on the computer, I thought the image was rather dull and boring. So, I decided to have a play in PhotoShop, and the idea of isolating the train came to mind:
I was rather pleased with the result.