Hi

Do you mean the colour of the top address bar?If so, the best way to change the colour of this is to go to addons.mozilla.org and select a new theme that would darken that part if the screen.

I hope that this helps, but if not, please come back here and we can look into a different solution for you.

Hi, thanks for the help, once I found the themes I seen you had replayed, this kinda helped but don't get why only the out side or the borders change, but not the hole web pages, I get why, cause the other we. Page's are not formatted for this dark mode, but It's 2019, and we should be pass this and on to the next new thing.. lol but anyways thank you again for the information..

Hi

You may wish to try Firefox Preview (available from the Google Play Store). This is a new browser from Mozilla that does have a dark theme that also dark themes web pages such as Twitter automatically.