The current default admin theme "Seven" in Drupal 8 was picked up from Drupal 7 with some modifications and since then we didn't see many changes in it. Admin theme is one of the first interactions of site owners with Drupal and not having a modern admin design out of the box.
Claro theme is a result of the Drupal admin UX Study in which content editors were asked to share their experiences and suggestions. And one of the biggest outcomes was that the Drupal admin interface is not that appealing to first-time users.
Here is how the new Claro admin theme looks like.
Claro theme is still in the experimental state but this is something that can be enabled or disabled any time if you find any blocker issue. So if you haven't tried the new Claro admin theme then you are missing on an amazing admin experience on your Drupal 8 site, just give it a try.
How to enable Claro admin theme in Drupal 8:
- First thing first, update to Drupal 8.8.0.
- Log in as administrator and go to `admin/appearance`.
- Look for the "Claro 8.8.0 (experimental theme)" theme and click on "Install". Note: Don't click on "Install and set as default" because it will make Claro as your default theme for the frontend as well.
- Once the Claro theme is installed, scroll down to the "Administrator Theme" section, select "Claro (Experimental)" from Administrator theme options and submit.