This add-on allows you to set dark theme for messenger.com.
Features:

• Change and tweak colors of text, background etc.
• Toggle between bright (default) and dark colors of text for better readability on certain chat colors. This option was preset but not yet implemented after introduction of the new messenger layout.

If you're experiencing issues with new facebook layout, try to update this addon.

Source code: https://github.com/Headary/messenger-dark-theme

Install

• License: Mozilla Public License 2.0
• Weekly downloads: 113
• Average daily users: 5006
• Rating: 4.5818/5 of 55 ratings
• Created: 2019-04-15 15:51:50
• Last updated: 2022-10-29 15:30:18
• Homepage:
• Support site and email
• Orig: https://addons.mozilla.org/en-US/firefox/addon/messenger-dark-theme/
• API: {2c6efd7e-6963-4cd4-b592-68481085db6d}