Baggrundsfarve i tekstliste

Hvordan får jeg indsat en baggrundsfarve i listen på nedenstående kode?
<html>
<head>
<script>
opts = new Array("Mikkel", "Mus", "Bi"); //Ordene

opts.sort();
function opdater(frm) {
sg = frm.ord.value.toLowerCase();
lt = new Array();
for (i = 0; i < opts.length; i++)
if (opts[i].toLowerCase().indexOf(sg) == 0)
lt[lt.length] = opts[i];
frm.liste.length = lt.length;
for (i = 0; i < lt.length; i++) {
frm.liste.options[i].value = lt[i];
frm.liste.options[i].text = lt[i];
}
frm.liste.selectedIndex = -1;
}
</script>
</head>
<body onLoad="document.frm.ord.value = ''; document.frm.liste.selectedIndex = -1; document.frm.ord.focus();">
<Center><form name="frm">
<input type="text" name="ord" onKeyUp="opdater(this.form);" style="width: 160px;">
<br>
<script>
document.write('<select size="' + opts.length + '" name="liste" style="width: 160px;"onchange="location.href=this.value+\'.html\';">');
for (i = 0; i < opts.length; i++)
document.write('<option value="' + opts[i] + '">' + opts[i] +'</option>');
document.write('<select>');

</script>
<br><br>
<input type="submit" value="Send">
</form>
</body>
</html>