Bartik Admin - Always Super Admin theme as a Batrik theme.
We don't want to mess up with other topics during the growth. It's just a development-friendly developer. We must always set the superadmin as a bartik. If you want, the configuration settings can be overridden. Only the superadmin user (Superadmin UID=' 1') will be accessible.
Super administration theme will be override the admin pages as batrik. Drupal allows you to define a different theme for administration pages.
An option for overriding the other activated topics was given.
The configuration page shows only allowed topics if you want to overwrite the superadmin theme goto profile page (user/1/bartik-admin).
If Bartik theme is disabled means, it will take the default ADMINISTRATION THEME (/admin/appearance) as a superadmin user.