Try to clear the cache and history and reset your browser settings

It's possible that your browser is not saving your theme preferences properly, which is causing it to revert to the previous theme when you open the browser. Here are a few troubleshooting steps you can try to resolve this issue:

Clear your browser cache and cookies: Sometimes, issues with theme preferences can be caused by corrupted cache or cookies. Clearing them may help to resolve the issue. To do this, go to your browser settings and find the option to clear your cache and cookies.

Disable or remove the theme you created: It's possible that the theme you created is causing conflicts with your other themes. Try disabling or removing the custom theme to see if that resolves the issue.

Update your browser: Outdated browser versions can sometimes cause issues with theme preferences. Make sure your browser is up-to-date with the latest version.

Reset your browser settings: If none of the above steps work, you can try resetting your browser settings to their default values. This will clear all settings, including themes, so you will need to reconfigure them after resetting.

If none of these steps work, it may be worth reaching out to the support team for your browser to see if they can help you troubleshoot the issue further.

You can try Firefox from the official Mozilla server if you currently use a version from the repositories of your Linux distribution to see if it behaves differently.

• https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

It's possible that your browser is not saving your theme preferences properly, which is causing it to revert to the previous theme when you open the browser. Here are a few troubleshooting steps you can try to resolve this issue: Clear your browser cache and cookies: Sometimes, issues with theme preferences can be caused by corrupted cache or cookies. Clearing them may help to resolve the issue. To do this, go to your browser settings and find the option to clear your cache and cookies. Disable or remove the theme you created: It's possible that the theme you created is causing conflicts with your other themes. Try disabling or removing the custom theme to see if that resolves the issue. Update your browser: Outdated browser versions can sometimes cause issues with theme preferences. Make sure your browser is up-to-date with the latest version. Reset your browser settings: If none of the above steps work, you can try resetting your browser settings to their default values. This will clear all settings, including themes, so you will need to reconfigure them after resetting. If none of these steps work, it may be worth reaching out to the support team for your browser to see if they can help you troubleshoot the issue further.

I cleared my cache and it seemed to work when I restarted my computer and browser, but then when I woke up this morning my created theme came back on... might be time to reset my settings, so long as it wont bork my bookmarks

Hi

Do you have the Firefox Colour add-on installed?

If so, uninstalling this may help remove the theme that keeps reappearing.