Does someone know how to assign materials to cable trays, I already know how to apply filters so please don't answer about filters?
Currently (as of Revit 2014), one can only assign a Material to Cable Tray though Object Styles, which means that it is not possible for different Types of Cable Tray to have different Materials. The Material of Ducts and Pipes are defined by their respective System Types, which does not currently exist for Conduit and Cable Tray, but maybe one day in the future...
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Autodesk Product Support"The following link is setup for you to submit feature requests, or feedback, directly to our Development group:"
http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=1109794