리스트메뉴 (select 버튼)에 색상 삽입하기

<html>
<head>
<style type="text/css">

</style>
</head>

<body>
<center>
<form>
<select name="job" class="format">
<option value="">선택하세요+++</option>
<option value="교사">교사</option>
<option value="학생">학생</option>
<option value="기타">기타</option>
</select>
</form>
</center>
</body>
</html>