In sample URI, "option" elements are rendered with CSS pseudo class "valid". According to HTML5 specification, "option" elements don't support it. http://www.whatwg.org/specs/web-apps/current-work/multipage/selectors.html#pseudo-classes == Browser Compatibility == * Firefox OK * IE doesn't support background color in listbox * Opera OK == Sample HTML == <head> <style type="text/css"> select:valid { background: blue; } option:valid { background: red; } #one { background: green; } </style> </head> <body> <ul> <li>One's background green</li> <li>Other's background is blue</li> </ul> <select size="5"> <option id="one" value="1">One</option> <option value="2">Two</option> <option value="3">Three</option> <option value="4">Four</option> </select> </body>
*** This bug has been marked as a duplicate of bug 80088 ***