I am starting to pull my hair out trying to remove an appearance off a surface.   I RMB on the surface and select the appearances icon, select the face level where I can see the colour and when the Appearances property box opens up on the left the face is listed but the 'Remove Appearance' is greyed out.   I have tried to delete the surface in the 'Selected Entities' box and pressing ok - no help, as soon as I rebuilt, the colour is back.  I don't want any appearance on any face anymore, just at part level.  Anybody out there that can help?