TST is unexpectedly using darker background color on Firefox v89.0 and default theme

[cosmo0920]

Short description

After I upgrade Firefox to v89.0, TST starts to use "darker" background color with default theme.
But, tab bar still use gray color that I expected to be used in TST.

Steps to reproduce

1. Start Firefox with clean profile.
2. Install TST 3.8.2.
3. Use TST with Firefox v89.0 and use default theme.
4. Background color glitch is occurred.

Expected result

When with default theme and not to be enabled night mode, the following appearance I'd expected.

Actual result

When with default theme and not to be enabled night mode, I got the following appearance. (TST uses darker background)

Environment

• Platform (OS): Ubuntu 18.04 Bionic
• Version of Firefox: 89.0
• Version (or revision) of Tree Style Tab: 3.8.2

[piroor]

This is intentional. Currently TST's theme color for Linux is made for the default theme of Ubuntu. Here is a screenshot on Ubuntu 20.04LTS:

Sadly Firefox doesn't provide ability to know the exact background color of the native tab bar on GNOME3 to extensions. So I had to decide just one from possible colors. I thought that inverted menu color (system colors Menu and MenuText: I use Menu as the text color, MenuText as the background color) looks natural on this environment.

Here is a workaround user styles to override those colors:

:root[color-scheme="system-color"][data-user-agent*="Linux"]
  tab-item:not(.active):not(.bundled-active):not(.highlighted),
:root[color-scheme="system-color"][data-user-agent*="Linux"]
  .after-tabs button,
:root[color-scheme="system-color"][data-user-agent*="Linux"]
  .after-tabs [role="button"],
:root[color-scheme="system-color"][data-user-agent*="Linux"]
  #subpanel-selector-anchor,
:root[color-scheme="system-color"][data-user-agent*="Linux"]
  #background {
  --toolbar-non-lwt-bgcolor: (something background color);
  --toolbar-non-lwt-textcolor:(something foreground color);
}

[cosmo0920]

Sadly Firefox doesn't provide ability to know the exact background color of the native tab bar on GNOME3 to extensions. So I had to decide just one from possible colors. I thought that inverted menu color (system colors Menu and MenuText: I use Menu as the text color, MenuText as the background color) looks natural on this environment.

Oh, that's too bad.
I'm using Adwaita GNOME3 theme for a long time.

[cosmo0920]

I also found the workaround for this issue which is choosing light theme as already noted on "Expected result".
Thanks for the quick help.

[piroor]

Anyway, I still need something better solution about this problem...

[cosmo0920]

Hmm..., should I reopen this issue to store our TODOs?

[piroor]

I've added a new code snippet: https://github.com/piroor/treestyletab/wiki/Code-snippets-for-custom-style-rules#change-background-and-foreground-color-of-the-sidebar-on-the-combination-proton-and-linux-2942

I think this issue should stay closed because currently there is no available better solution. Just for references I put links to bugs of Firefox related to this:

1542044 - browser.theme.getCurrent() & onUpdated should take in account dark_theme manifest field
https://bugzilla.mozilla.org/show_bug.cgi?id=1542044
1435216 - Return something useful for theme.getCurrent() when the default theme is applied
https://bugzilla.mozilla.org/show_bug.cgi?id=1435216

[cosmo0920]

Sure. That's make sense.

[cosmo0920]

And I edited this part ( https://github.com/piroor/treestyletab/wiki/Code-snippets-for-custom-style-rules#change-background-and-foreground-color-of-the-sidebar-on-the-combination-proton-and-linux-2942 ) for readability.