Photoshop process for production stills

During the filming of my music video I took a series of production stills for the ancillary tasks. I used Photoshop to edit the photos. All of the photos were taken against a plain brick wall. In Photoshop I made the brick wall black and white in all of the photos and I left the subjects in colour in the foreground. This is an example of what each photo will look like:

Before:

After: