Rated 4 out of 5 stars

The Monterail Dark and Full Dark themes look great. It's great that now there is an easy way to install the Monterail themes and that they work better with the Write Window.

The developer resolved the conflicts with the other Monterail themes. Now you can have multiple Monterail themes installed!

Just reinstall the theme following the steps mentioned by the dev.

Also, when the thunderbird window is maximized in Windows 10, the tab/minimize/maximize/close titlebar is cropped (noticeable when hovering the mouse over them).

Also, the Calendar sidebar does not assume the theme colors.

This review is for a previous version of the add-on (1.0.3).  This user has other reviews of this add-on.

All these issues are resolved with version 1.1!