What Does the Add-on Do? While you browse the web, this add-on changes the theme of Firefox to match the appearance of the website you are viewing — just like how macOS Safari tints its tab bar. Works Well With:

Incompatible With:

Firefox versions older than 112.0 (released in April 2023)
Adaptive Theme Creator
Chameleon Dynamic Theme
VivaldiFox
Envify
and any other add-on that changes the Firefox theme

If You’re Using a CSS Theme: A CSS theme can work with ATBC (Adaptive Tab Bar Colour) when system colour variables are used (e.g. --lwt-accent-color for tab bar colour). This is an example of an ATBC-compatible CSS theme. If You’re Using Linux with a GTK Theme: Firefox’s titlebar buttons may revert to the Windows style. To prevent this, open Advanced Preferences (about:config) and set widget.gtk.non-native-titlebar-buttons.enabled to false. (Thanks to @anselstetter) Safety Reminder: Beware of malicious web UIs: Please distinguish between the browser’s UI and the web UI. See The Line of Death. (Thanks to u/KazaHesto) Feel free to star this project on GitHub: https://github.com/easonwong-de/Adaptive-Tab-Bar-Colour