<html>
<head>
<style>
option:disabled {
background-color: lighgray;
}
</style>
</head>
<body>
<h1>Demo of :disabled</h1>
<select>
<option value="volvo">Volvo</option>
<option value="saab" disabled>Saab</option>
<option value="opel">Opel</option>
<option value="audi" disabled>Audi</option>
<option value="bmw">BMW</option>
</select>
</body>
</html>