You can see that CSS code with the titlechanged atrribute in browser.css

• chrome://browser/skin/browser.css

You can override the rules by applying the default tab appearance.

Add code to userChrome.css below the default @namespace line.

• http://kb.mozillazine.org/userChrome.css

The customization files userChrome.css (interface) and userContent.css (websites) are located in the chrome folder in the user profile folder.

• http://kb.mozillazine.org/Editing_configuration

.tabbrowser-tab[pinned][titlechanged]:not([selected="true"]) {
  background: -moz-linear-gradient(hsla(0,0%,100%,.2), hsla(0,0%,45%,.2) 2px, hsla(0,0%,32%,.2) 80%) !important;
}
.tabbrowser-tab[pinned][titlechanged]:not([selected="true"]):hover {
  background-image: -moz-linear-gradient(hsla(0,0%,100%,.6), hsla(0,0%,100%,.2) 4px, hsla(0,0%,75%,.2) 80%) !important;
}

Hi cor-el,

I am not a programmer, so I hope you can provide some further help. I found the userChrome_example.css file using the links you provided (thanks!). I edited it to add the entirety of the code you provided below the @namespace line, saved-as "userChrome.css" in the same chrome folder and restarted Firefox. I still get the blue notification glows. Can you tell me what I'm doing wrong? Do I also need to edit and add this code to the userContent.css file? Thanks in advance.

Check the properties of the userChrome.css file via the right-click context menu to be sure that the file type is Cascading Stylesheet and not Text Document.

I am using a Mac, so I confirmed with Get Info that it is indeed a CSS document. Its default is to open with Safari.

If it isn't working then try to add -moz-appearance: none !important;

.tabbrowser-tab[pinned][titlechanged]:not([selected="true"]) {
  background: -moz-linear-gradient(hsla(0,0%,100%,.2), hsla(0,0%,45%,.2) 2px, hsla(0,0%,32%,.2) 80%) !important;
 -moz-appearance: none !important;
}
.tabbrowser-tab[pinned][titlechanged]:not([selected="true"]):hover {
  background-image: -moz-linear-gradient(hsla(0,0%,100%,.6), hsla(0,0%,100%,.2) 4px, hsla(0,0%,75%,.2) 80%) !important;
}

That didn't do it either. <sigh>

hello, a workaround might be the experimental "suspend background tabs" extension - it will restrict the updating of any but the active tab & therefore may reduce/remove the glowing indicator on the app-tabs as a by-product. although it was developed with another goal in mind (performance of the browser) it might also work for your purpose...

https://addons.mozilla.org/firefox/ad.../suspend-background-tabs/

It works for me on Linux.

Are you using a custom theme or the default theme or tab related extensions that may override the code?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

The experimental "suspend background tabs" extension that madperson suggested does exactly what I need! And hopefully improves the browser performance. Thanks! I'm going with this instead of continuing to try to monkey around with coding.

Hi cor-el,

I want tabs to highlight/glow when they change not for app tabs but for "normal" tabs.

Can you help me?