list-style-image:none !important;
-moz-image-region:auto!important;

Just posting this to confirm that the solution provided by cor-el in an archived thread (four years ago) works, if you want to change your bookmark folder icons. [[ https://support.mozilla.org/en-US/questions/1210566| https://support.mozilla.org/en-US/questions/1210566]] After clicking the top right menu icon from the browser, going to Help > More Troubleshooting Information, and then opening the Profile Folder location, I added a `chrome` folder to the root of the directory, and created an empty `userChrome.css` file within it. I then added the following to `userChrome.css`. On startup it successfully changed the folder icons (I just didn't want any icon for each folder, so I set it to none): ``` @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */ #personal-bookmarks .bookmark-item[container], #bookmarksMenuPopup .bookmark-item[container] { list-style-image:none !important; -moz-image-region:auto!important; } ```