Hi,
Thank you for this plugin.
It seems it is impossible for users to select the default Redmine theme (which part of redmine core) as it doesn't appears in the theme list. The only why to use the default theme is to make it default in the system, and to not specify a custom theme in the user preference. But as we use a custom theme in the system, there is no way to switch a specific user to the default theme.
Is it fixable ?
Pierre