<!DOCTYPE html>
<html>
<head>
<style type="text/css">
    optgroup:disabled { color: pink; }
    optgroup:enabled { color: green; }
    option:disabled { color: red; }
    option:enabled { color: blue; }
</style>
</head>
<body>
<form>
<select size="20">
<optgroup label="Enabled">
    <option value="listbox_e11">One</option>
    <option value="listbox_e12">Two</option>
    <option value="listbox_e13">Three</option>
    <option value="listbox_e14">Four</option>
</optgroup>
<optgroup label="Disabled" disabled>
    <option value="listbox_d1">One</option>
    <option value="listbox_d2">Two</option>
    <option value="listbox_d3">Three</option>
    <option value="listbox_d4">Four</option>
</optgroup>
<optgroup label="Enabled2">
    <option value="listbox_e21">One</option>
    <option value="listbox_e22" disabled>Two</option>
    <option value="listbox_e23" selected>Three</option>
    <option value="listbox_e24">Four</option>
</optgroup>
</select>
<br />
<select size="1">
<optgroup label="Enabled">
    <option value="listbox_e1">One</option>
    <option value="listbox_e2">Two</option>
    <option value="listbox_e3">Three</option>
    <option value="listbox_e4">Four</option>
</optgroup>
<optgroup label="Disabled" disabled>
    <option value="menulist_d1">One</option>
    <option value="menulist_d2">Two</option>
    <option value="menulist_d3">Three</option>
    <option value="menulist_d4">Four</option>
</optgroup>
<optgroup label="Enabled2">
    <option value="listbox_e21">One</option>
    <option value="listbox_e22" disabled>Two</option>
    <option value="listbox_e23" selected>Three</option>
    <option value="listbox_e24">Four</option>
</optgroup>
</select>
</form>
</body>
</html>
