You can always Copyright your work.
In the U.S.
The Copyright Act states that “pictorial, graphic, and sculptural works include two-dimensional and three-dimensional works of fine, graphic, and applied art, photographs, prints and art reproductions, maps, globes, charts, diagrams, models, and technical drawings, including architectural plans.” (17 U.S.C. § 101)
Copyright in a work of the visual arts protects those pictorial, graphic, or sculptural elements that, either alone or in combination, represent an “original work of authorship.”
You might not be able to Copyright the configuration file but you can Copyright the graphics or the art work. Just like a photographer or a graphic artist.