gistfile1.txt

$.each($("#select1 > option"), function (index, item) {
  var found = false;
  $.each($("#select2 > option"), function (index1, item1) {
   if(item1.text == item.text) {
    found = true;
   }
  });
  
  if(found) {
    $(item).css("background-color", "red");
  }
});