Hi, try this: Type about:config into the address bar, press Enter and accept the warning. Now right click on any entry > New > Integer, and enter ui.systemUsesDarkTheme > OK, then in the next box, enter 0 (that's a zero) > OK.

Note: Should you make a mistake and want to remove the entry, right click > Reset, then restart Firefox.

Also make sure that browser.in-content.dark-mode is set to False (double click the entry to change it if set to True.)

Now restart Firefox.

If your question is resolved by this or another answer, please help other users by marking the best reply as Solved. Thank you!

I don't want you to think I'm ignoring you. I haven't had a chance to try this yeat. I'll let you know when I'm on the computer at a time when I feel I have enough brain power to try it

The other involves opening the Settings app. Navigate to “Control Center.” Then, find “Customize controls,” and you'll see an option to add Dark Mode to your Control Center.

To turn on Dark Mode in iOS :

   Tap on the Settings app.
   Scroll down and tap on “Display & Brightness”
   Select “Dark Mode”

https://www.theverge.com/2019/3/22/18270975/how-to-dark-mode-iphone-android-mac-windows-xbox-ps4-nintendo-switch

Hi Senali Madawala, you mentioned:

To turn on Dark Mode in iOS :

Please note next to the question the "Question details" section where the user indicates this question is for Windows 10.

I know how to turn it on. I want to know how to turn it OFF.

Hi Ellen, please try the steps listed by SeburoScribe in the first reply.

Sorry about that!

I didn't see a reply from anyone named Seburo.

Ellen said

I didn't see a reply from anyone named Seburo.

I'm sorry, I meant Scribe. Sorry, Scribe!

Scribe said

• Hi, try this:
  • Type about:config into the address bar, press Enter and accept the warning.
  • Now right click on any entry > New > Integer, and
  • enter ui.systemUsesDarkTheme > OK, then in the next box,
  • enter 0 (that's a zero) > OK.

• Note: Should you make a mistake and want to remove the entry, right click > Reset, then restart Firefox.

• Also make sure that browser.in-content.dark-mode is set to False (double click the entry to change it if set to True.)

• Now restart Firefox.

I already answered Scribe. I haven't had time to try this yet.

when your operating system is set to dark mode, all of Firefox's internal pages will reflect that fact, including preferences and privacy settings.

   Check out our guide to the best browsers
   Find out how to activate dark mode in Chrome
   The best free password manager

My OS isn't set to dark mode.

Scribe, thank you so much. I finally got up the nerve to try your solution, and it worked.