I'm writing a Drupal installation profile for Drupal 9+. I notice that in versions of Drupal prior to 9.5, Drupal uses the "Seven" theme during installation. After Drupal 9.5, it uses "Claro".
During the installation process, I'd like to use a sub-theme of either Seven or Claro, but that has a custom logo and color scheme. Is there a way to do this?
Yes! Support for this was implemented way back in the early Drupal 8 releases, as part of #1351352.
In the .info file for the installation profile, add the distribution.install.theme key.
For example:
name: 'My Distribution'
type: profile
core_version_requirement: ^9 || ^10
package: 'My Package'
distribution:
name: 'My Distribution'
install:
theme: claro
You can change the distribution.install.theme setting to any theme that's packaged with the distribution. It will automatically get loaded.