However, just to give you that extra highlighting of a website thats claims to be secure, you can choose to display the website domain or the subdomain highlighted in a Blue background next to the FavIcon of the website.
To do so, open a Firefox browser and type “about:config” in the address bar and press enter. Click the button “I’ll be careful, I promise!” button.
Type “browser.identity.ssl_domain_display” in the filter. Double-click the entry and set the following values:
1 – Show the top level domain (ex: google.com)
2 – Show the full domain including the subdomain (ex: www.google.com)