Magento 2 module to add CLI commands to manage themes from the command-line

composer require yireo/magento2-theme-commands
bin/magento module:enable Yireo_ThemeCommands

List all themes:

bin/magento theme:list

List all assigned themes (aka design configurations):

bin/magento theme:design_config

The theme:design_config output also shows an Override column, which identifies whether a specific value (like, a theme ID for a specific Store View) is indeed overriding the default or not.

Change the current theme to Magento/luma for all scopes:

bin/magento theme:change Magento/luma

Note that the theme:change command also includes a flag --reset (valid only without additional parameters) which resets all stores to the default, so that only 1 theme is active:

bin/magento theme:change --reset -- Magento/luma

Change the current theme to Hyva/default for the StoreView with ID 1:

bin/magento theme:change Hyva/default 1 stores

Create a new theme:

bin/magento theme:create --theme Yireo/example --parent Magento/luma --application frontend
bin/magento theme:change Yireo/example