table.dataTable thead .sorting:after, 
table.dataTable thead .sorting_asc:after, 
table.dataTable thead .sorting_desc:after {
  color : black;
  opacity: 1 !important; 
}
table.dataTable thead .sorting:before, 
table.dataTable thead .sorting_asc:before, 
table.dataTable thead .sorting_desc:before {
  color : black;
  opacity: 1 !important;
}