A universal dark theme for Thunderbird
Clone or download
Latest commit 6cc2a3d Oct 14, 2018



ShadowBird is a spinoff of ShadowFox (GitHub Link), a universal dark theme for Firefox 57+, designed for Thunderbird.

This project is early in development and users are encouraged to open issues or pull requests with any problems, enhancements or feature requests.




  1. Enable the default dark theme (Tools > Add-ons > Theme > Dark)

  2. Download this repository and rename the folder to chrome.

  3. Place the chrome folder inside your Thunderbird profile directory. To find your profile directory, you can do the following from within Thunderbird:

    • Help > Troubleshooting Information > Application Basics section > Profile Folder > Show in Finder
  4. (Optional) To change the background and text area of the message composition pages, you can dd the following lines to your user.js file within the profile directory (this will not alter the appearance of sent messages):

user_pref("browser.display.foreground_color", "#b1b1b3");
user_pref("browser.display.background_color", "#38383d");

The user.js does not exist be default; you will have to create the file (name and case sensitive) if you haven't done so in the past.

  1. Restart Thunderbird