Firefox never added support for colored title bars in Windows 10. Initially, title bars in Windows 10 had no color. Users resorted to UI modifying apps and themes to get colored title bars until the feature was added natively. Once it was added though, Firefox choose to sit the feature out. A hack for the shortcoming was quickly developed by modifying the userChrome.css file. Unfortunately, Firefox 40 removed this file and the hack became obsolete. Here’s how you can get colored title bars in Firefox, regardless which version of the browser you’re running.
Firefox 39 And Below
If you’re running anything older than Firefox 40, you can use the old hack. You have to modify the userChrome.css file in order to get colored title bars in Firefox.
Go to about:support and scroll down to the profile row. Click ‘Show Folder’. In the folder that opens, look for a folder called ‘Chrome’. Inside this folder is the userChrome.css file. Open it in Notepad.
Add the following code to the end of the file and save it.
@-moz-document url(chrome://browser/content/browser.xul) {
@media (-moz-os-version: windows-win10) {
#main-window:not([customizing]){
-moz-appearance: -moz-win-glass !important;
background-color: transparent !important;
}
}
}
Restart the browser and you will have colored title bars in Firefox.
Firefox 40 and above
With the userChrome.css file gone in Firefox 40 and above, you need a new way to modify the browser’s UI. Install the Classic Theme Restorer add-on. Go to the add-on’s options and select the ‘Custom css code’ tab from the left. Paste the following code in it and you will have colored title bars in Firefox.
@-moz-document url(chrome://browser/content/browser.xul) {
@media (-moz-os-version: windows-win10) {
#main-window:not([customizing]){
-moz-appearance: -moz-win-glass !important;
background-color: transparent !important;
}
}
}
There is one shortcoming with this hack; it won’t work in Firefox 57 and above. Mozilla plans to change how add-ons work in Firefox 57. In the course of that change, this add-on will become obsolete. Perhaps by then Mozilla will have added support for colored title bars in Firefox. If nothing else, another add-on is bound to be developed.