User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0

Steps to reproduce:

Update to Firefox 89.0

Actual results:

The Titlebar of the Firefox windows is BRIGHT and does not follow the colour of the operating system theme. (Windows 10 version 20H2).
Other browsers (or any application for that matter) have a light gray Titlebar colour and a dark gray for the front window.
Firefox System 89 theme claims to "Follow the operating system setting for buttons, menus, and windows" but is actually using the Light theme colour.

Expected results:

The TitleBar colour for Default Theme should match the operating system. (just as in the version before Firefox 89, and just as in its own description).

The Bugbug bot thinks this bug should belong to the 'Firefox::Theme' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

You can set a custom accent color for the tilte bars in windows 10.
It is completely ignored by FF 89.

I can confirm this. The system theme is now the same as the light theme...

Hi Tudor, thank you for taking the time to report this issue, I tried to reproduce this issue on my end on a Windows 10 machine but without success, maybe I missunderstood the issue can you please clear a few things up for us:

1. By "Title bar" are you reffering to the Title bar a user can check/uncheck from Customize Toolbar page ? Right Click on the Toolbar > Customize Toolbar > Bottom left > Checkbox for "Title bar" ?
2. When you select the color of the Operating System theme are you also checking the "Title bars and Windows borders" checkbox from the "Show Accent color on the following surfaces" section ?

The Title bar will always have the OS selected color, however the Tabs bar and Toolbar are not affected by the OS color, only by the Firefox Theme "Light, Dark, Alpenglow.." which I believe its by design implemented in FX 89.

Rares, I sent you screenshots via email. The light and system theme are exactly the same.

Hi Futschigama, you are correct the Firefox Light and Default themes are almost identical, I tried to get the Color Code for each team and I got:

Default Theme:
Toolbar: F9F9FB
Tabs bar: F0F0F0

Light Theme:
Toolbar: F9F9FB
Tabs bar: F0F0F4

I was using the Windows Free Color picker in order to sample the colors, but I think this might need to be tracked in a separate bug as for the main issue here is that the Title bar is not respecting the OS color which I was unable to reproduce, I will attach a screenshot of how it Looks on my end.

Maybe this is a different issue than OPs, you're right. I just find it hard to believe that Firefox would make the default theme so much like the light theme and nobody else is bothered by it. It's hideous. There is no contrast whatsoever. It just feels like an obvious bug to me.

I think I found out what the issue is, Since the new implementation, Firefox is forced to take the Operating Systems Color but at the same time If you reach the Windows settings > Colors page the only option there for "Choose your Default app mode" is Light or Dark and I think because of that option Firefox Default Theme will always be what is set there, which is Light by default I think, thats why when a user changes the Firefox Theme to Light there isnt much of a difference.

If you Reach Start > Personalization > Colors > Choose your default app mode and switch to Dark it will completely change the Firefox Default Theme to DARK.

I think before Firefox Hardcoded the colors for the Default theme and so the user would install a different theme or select one from the existing ones, Light or Dark.

Please find attached the screenshot sample for an active window on top of an inactive window.
In Firefox 89, with System theme both active and inactive windows are light/silver colour ( same colour or indistinguishable ).
For reference, the are also a snapshots of Firefox 89 with about:config "browser.proton.enable false", Edge and Chrome. For all those the behaviour is: grey active window/ light grey inactive window on par with the expectations of my Windows colour settings.

This issue does occur but I think it might be intended with the new Proton design , disabling browser.proton.enable = false will no longer cause Firefox to take the Windows colors and that specific "Choose your default app mode" option into consideration.
Maybe one of our developers can take a look and explain this a little better than me, and if this is not a valid issue we can mark it as invalid or a wont fix if its intended behavior.

I think there are maybe two issues in this bug.

• Accent colors from windows aren't used at all (bug 1701266)
• It's hard to differentiate inactive and active windows (bug 1704131)