When you change the graphic display of layers in a linked file, you can specify whether Revit preserves or discards the graphic overrides.
When you preserve graphic overrides, Revit retains any changes made to the graphic display of its layers when it reloads the linked file. Otherwise, Revit discards graphic overrides when reloading the linked file. This option applies to all CAD files that are linked to the project.
To preserve or discard graphic overrides for linked files