Administration: Ensure the Theme Feature Filter button use the new default Admin colors.

Props niravsherasiya7707, louischan, penelopeadrian, noruzzaman, valentingrenier.
Fixes #64808.



git-svn-id: https://develop.svn.wordpress.org/trunk@61850 602fd350-edb4-49c9-b593-d223f7449a82