There are 2 repositories under browser-theme topic.
A theme that aims to look nice and clean while not compromising functionality.
Minimize your Firefox toolbar to one single line [MIRROR]
Native app used alongside the Pywalfox addon
BlueCalm is a theme for various operating systems and browsers designed to look good and be calming.
The best dark mode web browser theme for your favorite web browser. That makes browsing the web more comfortable. The dark theme is for the following web browser Google Chrome, Firefox, and Microsoft Edge.
Web Browser Themes/Skins based on Init7 branding
🌳️🌐️🎨️ The Bliss Browser themes module, enabling browser themes, and allowing them to be displayed correctly.
A theme I createt for my Firefox browser
trollface browser theme for chrome
Custom CSS implementation to make Firefox look and feel more like a Chromium browser
Google I/O 2010 official theme for Mozilla Firefox