When exporting DWG from Revit, with the export option that all pipes and fittings are the same layer and export Color as "Export category properties BYLAYER and overrides BYENTITY "&"Specified in view (True Color - RGB values)", then the layer color of exported DWG is controlled by the first element in multiple categories that have different colors are set to be exported on the same layer. Please add an option to choose which category color should be used but not the first one.