Change IE background color on unopened, focused select box

Answer 1

I'm using the CSS below and it is working in latest IE11, Edge, Firefox and Chrome (I have not tested it with earlier browsers). Just remove border-radius and padding if you don't need them. And thanks to willrice for his contribution:

select {
  -webkit-appearance: none;
  -moz-appearance: none;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
  padding: 5px;
}

select:focus::-ms-value {
  background: white;
  color: black;
}

select::-ms-expand {
  display: none;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
  padding: 5px;
}