Galvanized cable trays can turn black for several reasons, but the most common drivers are wet storage stain, harsh industrial atmospheres (especially sulfur-related), chemical exposure, and coating damage during handling or installation. The filter setting is the only option on Revit. But in real projects, many users notice the surface turning gray-black, developing black spots, or dark streaks after storage, installation, or long-term exposure. Is there anyone who know how to make two different colour of cable tray in one revit project? Solved by johna. 10-21-2019 01:46 AM You can differentiate cable tray by using the filter option, where you can add. Changing the color of a cable tray in Revit requires a systematic approach to modify the appearance of the element within the project. Cablofil adapts to the most complex configurations, and its structure gives maximum strength for minimum weight.