User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

Using multi-account containers, open a tab in any container, then go to your settings and change the color for that container

Actual results:

The colored bar in the tab indicating what container is used did not update until reopening the tab

(it is unknown if this behaviour is avoided by closing any tab or closing all tabs of a container)

Expected results:

The colored bar in the tab indicating what container is used should change color to reflect the new setting

Demonstration of the bug

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

(In reply to Anselm Schüler from comment #0)

(it is unknown if this behaviour is avoided by closing any tab or closing all tabs of a container)

It is. See attached video.

Is this a regression? ISTR this used to work, but I could well be wrong...

I think this is not a regression. I can reproduce the issue on Nightly66.0a1(20190128092811) Windows10.

demonstration-of-other-situation

Tab color does update on the tab the settings page is in. See uploaded video.

(In reply to Anselm Schüler from comment #7)

Tab color does update on the tab the settings page is in. See uploaded video.

This does not invalidate this issue

There's code to do this but the code is just horribly broken.

Looks like bug 1344519 changed the observer notification but didn't update the tabbrowser consumer, and there were no tests.

https://hg.mozilla.org/mozilla-central/rev/d2032ecd7540