I am using IE9 and can't remove the blue background when a select dropdown is focused. When an item is selected from any of the drop downs the element is overlaid with a blue box. It doesn’t occur on Chrome or Firefox.
This code removes it for IE10 and Edge
select::-ms-value {
background: none; /* remove blue background on ie10/ie11 when selected*/
color:#5a5a5a;
}