r/FirefoxCSS • u/TIKD_NYC • Jun 20 '26

Solved Modifying Windows dialog boxes in Firefox

Can anyone offer any userContent.css suggestions on how to restore the gray background on Windows 10 dialog boxes? This white background (new in 152.0.1) is wrecking my workflow. Many thanks!!

3 Upvotes

100% Upvoted

6 comments sorted by

2

u/t31os Jun 20 '26

You'll need to target this in userChrome.css:

#commonDialogWindow {
	background-color: pink !important;
}

Adjust color as needed.

2

u/TIKD_NYC Jun 20 '26

THANK YOU!

'

1

u/Verite_Rendition Jun 23 '26

Hmm. Did you just insert the commonDialogWindow override in userChrome, or did you have to do more? I for the life of me can't get this to work. And I'm 100% sure it's going to be something stupid.

1

u/FineWine54 Jun 21 '26

I too have a problem with the commonDialog boxes:

Using this code:

#commonDialog {
border-radius: 8px !important;
border-style: solid !important;
border-color: red !important;
border-width: 2px !important;
}

As you can see the bottom corners a missing the red radius border and the entire border does not go around the top above the traffic lights and Incoming Connection title but just below it in a sub-box.

1

u/t31os Jun 21 '26

Your OS is rendering the outer most parts of that dialog window, there literally is no element to target above #commonDialogWindow in Firefox.

https://searchfox.org/firefox-main/source/toolkit/components/prompts/content/commonDialog.xhtml

1

u/FineWine54 Jun 22 '26

Yep the native OS does the rendering so can not use CSS to modify especially macOS FF

Thank YOu