Customize Edge of Shell or Edge of Shell Hole

Select the Customize Edge settings icon to open the Custom Edge Settings dialog box.
Note: By default, the Surface material applied to a Shell edge derives from the Building Material assigned to the Shell. You can override all edge surfaces of the Shell, using the controls in the Model Panel of Shell Settings. The Custom Edge Settings offers a further way to customize the surface of any one or more Shell Edges.
Surface: Click the Surface override button, then choose a custom surface for the Shell edge(s) or end surfaces.
If so, check the box at the bottom of Shell Settings (Apply changes to custom planes/edges too). If you do not check the box, your custom edge surfaces remain the way you set them.
Edge Type: Optionally, choose a type for the Shell edge.
Apply Changes to: Once you have set the options as needed, choose the edges to which to apply these changes:
Clicked Edge will apply the options you choose below (surface, edge type) only to the edge you clicked when bringing up the pet palette.
Selected Polygon will apply the chosen options to the extruded ends of the Shell only or the edges of the hole only, depending on which one is selected.
All Edges will apply the chosen options to all edges of the Shell as well as all edges of its holes.
Click OK to apply changes.