Why can't I change the font color of a submenu? _html/css_WEB-ITnose

	<div id='menu'>				<ul>					<li class='interval'>|</li>					<li><a href="index.html">首    页</a></li>					<li class='interval'>|</li>					<li>						<a href="#">研究方向</a>						<div id='submenu'>								<div class='subitem'><a href="1.html">- xxxxxxxxxx -</a></div>								<div class='subitem'><a href="1.html">- xxxxxxxxx -</a></div>								<div class='subitem'><a href="1.html">- xxxxxxxxxx -</a></div>								<div class='subitem'><a href="1.html">- xxxxxxxxxx -</a></div>						</div>					</li>					<li class='interval'>|</li>					<li><a href="topic.html">研究课题</a></li>					<li class='interval'>|</li>					<li><a href="team.html">研究团队</a></li>					<li class='interval'>|</li>					<li><a href="cooperation.html">交流合作</a></li>					<li class='interval'>|</li>					<li><a href="product.html">科研成果</a></li>					<li class='interval'>|</li>					<li><a href="passenger.html">毕业成员</a></li>					<li class='interval'>|</li>					<li><a href="contact.html">联系我们</a></li>					<li class='interval'>|</li>				</ul>

#menu {	padding:0px;	position:absolute;	margin:0 auto;	height:26px;	/*background:#ABC;*/	top:110px;	width:960px;	left:15%;	z-index:990;}#menu ul{	margin:0 auto;	position:absolute;	/*background:#00FF00;*/	list-style:none;	padding:0px;	height:26px;	line-height:26px;}#menu ul li{	float:left;	padding:0px;	height:26px;	line-height:26px;}#menu ul li a {	color:#7777CC;	display:block;	padding:0px 27px;	height:26px;	line-height:26px;	float:left;}#menu ul li a:hover {	background:#7777CC;	color:#EEE;}#menu #submenu {	position:absolute;	padding:0px;	float:left;	top:26px;	width:600px;	height:54px;	display:block;	background-color:#AAB;}.subitem {	width:600px;	color:#FF0000;}