Almost all brands of photo-management software have the ability to assign colored labels to you image files. It's been my experience with clients and students that the label feature is, more often than not, ignored or misunderstood. People ask me why—given the myriad combinations of keywords and other kinds of IPTC metadata (location, copyright, author, title, etc.)—one must also be concerned with the assignment of colored labels to our images. The answer is quite simple. It's visual.