I've created a rule in Graphic Overrides to highlight any element that is on the ArchiCAD layer and change it to a bright red colour.
The problem I'm having is that it also changes the in-built story levels in the elevation/section window to the bright red colour. I can't seem to exclude this from the rule as the in-built story level isn't a defined element that you can assign a layer to.
The work around is to define every element within the rule individually but it would be great if GS could fix this.
First don't create a rule in Graphic Override that shows all elements red in ArchiCAD layer. ArchiCAD layer is very good layer - because it cannot be hidden. So here you can keep some important elements - title blocks, drawings legends, placed drawings.
As about Storey Elevation markers - I think you can exclude them from selection by name (because it's a library part).