I agree, these pages are bright and annoying.  ;-)) A dark button like Google would be nice.

Note that extensions do not work on mozilla.org pages for security reason as Mozilla websites have advanced privileges like accessing all files on your computer and running special JavaScript.

Some simple changes can be done via userContent.css, but creating a dark theme is quite a challenge.

In the realm of "quick and dirty", you can invert the color scheme of the page and then tweak a few things to improve readability. This would be for a userContent.css file:

@-moz-document domain(support.mozilla.org){
  body {
    filter: invert(1);
    color: #600 !important; /* inverts to baby blue */
    background-color: #ddd !important;  /* inverts to dark gray */
    font-weight: 700 !important;  /* text needs bolding for readability */
  }
  textarea, input {
    font-weight: 700 !important;  /* text needs bolding for readability */
  }
  a:link {
    color: #066 !important;  /* inverts to salmon */
  }
  a:visited {
    color: #660 !important;  /* inverts to violet */
  }
  img {
    filter: invert(1) !important; /* double-invert inline images back to normal */
    background-color: #ccc !important; /* lighter bg for transparent images */
  }
  footer {
    filter: invert(1) !important; /* double-invert footer back to dark theme */
  }
}

Hi jscher2000, your solution is perfect and, of course, it doesn't interfere with dark mode in other pages.

Thank you very very much!

Prayan

Where/how do you put the code in?

https://www.userchrome.org/how-create-userchrome-css.html

Hi Paul, a userContent.css file is an optional file you can create to modify web pages (including built-in web pages). The way you set it up is nearly identical to a userChrome.css file, the difference being that a userChrome.css file is for modifying the user interface (toolbars, menus, etc.).

This is an unofficial / community-supported feature. If you are completely new to these files, one of us can detail the steps.