<a href="http://www.j-archive.com/media/2005-11-23_DJ_28.jpg" target="_blank">This</a> museum's <a href="http://www.j-archive.com/media/2005-11-23_DJ_28a.jpg" target="_blank">ducts</a> are color coded, blue for air, green for fluids, yellow for electrical, & red for movement