An extra theme is a directory in the user's theme folder that has no matching stock theme. Confirming runs omarchy-theme-remove. Escape, or a click on the faded backdrop, cancels. After the removal the list refreshes, and the selection lands on the theme that came before the one removed.

Removing the theme that is in use is allowed, matching the command-line remover. A folder that only customizes a stock theme stays, because it holds changes rather than a separate theme, and the command line can still remove it. David Heinemeier Hansson opened and merged the change. Hansson wrote in the pull request that the picker test passed, including confirm, cancel, and the cases that should do nothing.