JQuery Custom Select Box

HTML

<select id="s"  size="2">
    <option value="a">AA</option>
    <option value="b">BB</option>
</select>

CSS

select {
  width: 20%;
  padding: 2px;
  overflow: hidden;
}

select > option:checked {
  background: linear-gradient(pink, pink);
  color: black !important; /* doesn't work */
}