Customize jQuery UI Autocomplete Menu

HTML

<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css">
<input id="search_location_autointernal"/>

CSS

.dropdown-menu-1 li a {
   color: red;
}

JavaScript

$.widget( "ui.autocomplete", $.ui.autocomplete, {

      options: {
         renderItem: null,
         renderMenu: null
      },

      _renderItem: function( ul, item ) {
         if ( $.isFunction( this.options.renderItem ) )
            return this.options.renderItem( ul, item );
         else
            return this._super( ul, item );
      },

      _renderMenu: function( ul, items ) {

         if ( $.isFunction( this.options.renderMenu ) ) {

            //this.options.renderMenu( ul, items );
            
            
            			        var self = this;
			        var category = null;

			        var sortedItems = items.sort(function(a, b) {
			           return a.category.localeCompare(b.category);
			        });
			        
			        jQuery.each(sortedItems, function (index, item) {
            		
			            if (item.category != category) {
			                category = item.category;
			                ul.append("<li class=\'ui-autocomplete-group\'>" + category + "</li>");
			            }
			            self._renderItemData(ul, item);
			        });        



         }

         this._super( ul, items );
      },

   });

   var acMenu_Base = function( ul, items ) {

         $( ul ).addClass( 'dropdown-menu' );
      },

      acItem_Italicize = function( ul, item ) {
         return $( '<li>' )
            .append( $( '<a>' ).html( '<i>'+item.label+'</i>' ) )
            .appendTo( ul );
      },


   $( '#search_location_autointernal' ).autocomplete({
      source: [ { label: "Trullo di Monica", category: "titolo" }, { label: "Fasano", category: "comune" }, { label: "Trullo della Gioia", category: "titolo" }],

      renderMenu: acMenu_Base,
      renderItem: acItem_Italicize,

   });