Firefox won’t let me disable system theme syncing — ignores user.js and keeps resetting config (also: "System theme - auto")
I’m at my wits’ end with this. Firefox keeps forcing a system-synced theme at launch, and it flat-out refuses to respect the settings I’ve configured — both in about:config and via a custom user.js file.
Here’s what I’ve tried:
• Set layout.css.prefers-color-scheme.content-override to 0 in about:config → it reverts back to 2 after every restart.
• Created a user.js with user_pref("layout.css.prefers-color-scheme.content-override", 0); → completely ignored.
• Disabled all sync options, including themes.
• Verified that no active studies are interfering.
• Double-checked that I’m not syncing across devices.
• Tried applying a specific theme and setting it manually — still overridden at launch.
No matter what I do, Firefox insists on syncing the theme to the system’s dark/light setting. I want my browser theme independent from the OS — period.
Is there a deeper setting I’m missing? A hidden override? Some service that’s reapplying the system setting post-launch? This feels like Firefox is actively fighting me — and it's infuriating.
Would appreciate any insight or workaround. I just want full manual control over my theme. Why is that so hard?
所有回覆 (1)
1. Check for Conflicting Preferences Sometimes, other preferences can conflict with your theme settings. Here are a few additional preferences to check in about:config: • layout.css.prefers-color-scheme.content-override: Ensure this is set to 0 (as you have done). • ui.systemUsesLightTheme: Set this to 0 for dark mode or 1 for light mode. This preference can sometimes override your theme settings. • widget.content.gtk-theme-override: If you are on a Linux system, check this setting as it can affect the theme. 2. Disable Hardware Acceleration Sometimes, hardware acceleration can cause issues with how themes are applied. Try disabling it:
1. Go to Options (or Preferences). 2. Scroll down to Performance. 3. Uncheck Use recommended performance settings. 4. Uncheck Use hardware acceleration when available.
3. Create a New Profile If the issue persists, it might be worth creating a new Firefox profile to see if the problem is related to your current profile: 1. Type about:profiles in the address bar and press Enter. 2. Click on Create a New Profile and follow the prompts. 3. Launch the new profile and configure your theme settings to see if they are respected. 4. Check for Extensions Some extensions can interfere with theme settings. Disable all extensions temporarily to see if that resolves the issue:
1. Click on the menu button and select Add-ons. 2. Disable all extensions and restart Firefox.
5. Reset Firefox As a last resort, you can reset Firefox to its default state. This will remove all extensions and custom settings, but it may resolve the issue:
1. Click on the menu button and go to Help. 2. Select More Troubleshooting Information. 3. Click on Refresh Firefox.
6. Monitor for Updates Keep an eye on Firefox updates, as this could be a bug that gets resolved in a future release. You can also check the Mozilla Bugzilla to see if others are experiencing similar issues and if there are any reported bugs. 7. Report the Issue If none of the above solutions work, consider reporting the issue to Mozilla. You can do this through the Mozilla Support Forum or by filing a bug report on Bugzilla. Providing detailed information about your issue can help the developers address it in future updates. 8. Use a Custom User Style As a workaround, you can use a user style manager like Stylus to apply a custom theme that overrides the default settings. This can give you more control over the appearance of Firefox.
由 Mutaz Awad 於 修改