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 because you use a view template for that view. In newer Revit version, view template is persistent and it will not allow you to modify visibility/graphics.
If you want to modify the visibility, you can:
- Modify the view template. Remember that this will also change all views’ appearance that are using the same view template.
- Change your view template to <none> from properties palette. After you did that, you can modify the appearance using visibility/graphics overrides.