The involved CSS code can be found in this file that you can open via the location bar.

• chrome://global/skin/autocomplete.css

Look for class .ac-emphasize-text and apply modified rules as you like. You need to add the !important flag to override rules.

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

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

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */
@namespace html url("http://www.w3.org/1999/xhtml");

html|span.ac-emphasize-text {
  box-shadow: none!important;
  background-color: transparent !important;
  border-radius: 0px;
  text-shadow: none !important;
}

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

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

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

• Create the chrome folder (lowercase) in the <xxxxxxxx>.default profile folder if this folder doesn't exist
• Use a plain text editor like Notepad to create a (new) userChrome.css file in this folder (the names are case sensitive)
• Paste the code in the userChrome.css file in the editor window and make sure that the userChrome.css file starts with the default @namespace line
• Make sure that you select "All files" and not "Text files" when you save the file via "Save file as" in the text editor as userChrome.css. Otherwise Windows may add a hidden .txt file extension and you end up with a not working userChrome.css.txt file

Hi,

sorry it didn't work :

1. I have Firefox not Chrome

2. I couldn't find class .ac-emphasize-text in the about:config list in the address bar

Perhaps i've missed something, and perhaps it didn't work, I don't know

Thank you anyway :)

I haven't mentioned the about:config page in my above reply. Firefox uses the chrome: protocol to access build in files (files added by extensions as also accessed this way) and this has nothing to do with Google Chrome. You can past such an URL in the location bar and press Enter to view such a file (in this case a CSS file with style rules).

Did you try to create the userChrome.css file with the code I posted above?

I really thank you a lot, I think it is a good solution. I thank you for your detailed answer, and because you answered my question immediately. But it did not work with me: I tried understanding it many times, but the level was somehow higher than my potentials, I would rather seek a one-two-three-.. step method to tell me what to do, and not explain them, it would be easier for me :) Thanks anyway :)