I currently use a dynamo routine that adds a material. The material added will be named something generic like CHWS (for chilled water supply services. CHWR, CWS, Cond, etc. Then if the service name contains the name of the material, the material will be added to all parts in that service. This way the color is there for anyone who opens the Navis files. I have my developer writing a ribbon button for us so we don't have to rely on Dynamo as much going forward.