Interesting idea. Advanced settings are not as advanced as I would like for this to be actually usable. Time delay settings would be nice or a setting to wait until the tab is finished loading. Lots of false changes when the site is redirecting and flashing when it could be resolved by waiting a second. Turning off Dynamic Update of the tab color still sometimes has the tab color update, maybe when opening a new tab, but still distracting and against my wanted behavior. Amazing attempt, maybe Firefox's design disallows the true potential of this idea. I want a browser to do this seamlessly now.

Edit: appreciate the response!

I love this idea but I've had to disable it. On many sites I can't tell which tab is active. When you have many open its hard to hunt and peck when the highlight color is too similar to the rest of the theme.

The only disadvantage as for now is that when I type something in the search bar the first option is highlighted in bright blue. It would be nice to change that color as well.

Works very well but on some sites the color is slightly off.

Unfortunate oversight of the addon being that the bookmark overflow menu is not affected by the colour shift which makes the appearence of the browser ui inconsistent, which can be jarring. Would love to see this issue fixed.

When I open tab in new window, resize it and switch to a tab with another theme it gives me a seizure, flashing to dark and white very fast.