set focus color

focus.js

(function($){
  $.fn.colorFocus = function(color, trigger){
    var defaultColor = $(this).css('background-color');

    var hasTrigger = (typeof trigger == 'function');

    $(this).mouseover(function(e){
      if (hasTrigger && false == trigger(this)) return;
      $(this).css('background-color', color);
    });

    $(this).mouseout(function(e){
      $(this).css('background-color', defaultColor);
    });
  };
})(jQuery);