Adaptivetheme Base Theme
Download the latest version of Adaptivetheme for Drupal 8 and place in the
Nothing will show visibly on the themes list page
~/admin/appearance. This is normal, AT Core is a hidden theme that works in the background.
AT Tools & AT Theme Generator Modules
Download the latest verions of AT Tools module for Drupal 8 and place in the
The AT Tools module includes the theme generator in a sub-module called AT Theme Generator. Enable both modules from the Extend page
~/admin/modules in your Drupal site (or use Drush/Drupal console etc).
The next step is to generate a new theme, or install an existing sub-theme, such as Pixture Reloaded, AT Magazine etc.