You want to override your view visibility/graphics, but when you open the dialog box, you see all options are greyed. You can’t modify them.
The reason why you can’t modify them is that your view usea a view template. In the newer Revit version, the view template is persistent, and it will not allow you to change visibility/graphics.
If you want to modify the visibility, you can:
- Modify the view template. Remember that this will also change all views’ appearances that are using the same view template.
- Change your view template to <none> from the Properties Palette. After you did that, you can modify the appearance using visibility/graphics overrides.