Hi, I can't see the pictures, but for what you said, I think that Graphic overrides don't go inside an element, I mean that, you can not define a graphic override for the frames of the curtain wall and another for the panels, the same happens with objects, you can not override just one material of one part of the object, As far as I know, I hope to be wrong, and if I'm right I hope they keep developing GO for the next versions of Archicad to be able to do this.