This is my code

2. // On cache les sous-menus :
3. $(".menu ul.sub-menu").hide();
4. $('.menu ul.sub-menu li.current-menu-item').closest('ul').show();
6.   $(".menu ul.sub-menu li").addClass("sub-menu-item").removeClass("menu-item");
7. 
   
8.   $(".menu li.advanced > a").css("cursor","pointer");
9.  
10.   $(".menu li.advanced > a").click( function () {
11. 
    
12.   if ($(this).next("ul.sub-menu:visible").length != 0) {
13.   $(this).next("ul.sub-menu").slideUp("normal");
14.   }
15. 
    
16.   else {
17.   $(".menu ul.sub-menu").slideUp("normal");
18.   $(this).next("ul.sub-menu").slideDown("normal");
19.   }
20. 
    
21.   return false;
22.   });

This code works perfectlly, but I want to apply a specific style for sub-menu title tab. For example when sub-menu "Reseau Villes Numeriques" is opened, I want to apply a grey style on it. I try some parts of code, but nothing really works...You can see the menu  here.

Thank You