来帮我看看这个html 表格边框颜色怎么弄
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>
<style type="text/css">
<!--
.news table td{border:1px solid #F00;}
.bac table td{border:1px solid #00F;}
-->
</style>
<body>
<table width="658" height="317" border="0" cellspacing="0px" class="bac" style="border-collapse:collapse" align="center" id="t1">
<tr>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td colspan="2"><table width="50%" border="0" align="center" class="news" id="t2">
<tr>
<td>3</td>
<td>4</td>
<td>5</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
</table></td>
</tr>
</table>
</body>
</html>
<style type="text/css">
table.bac td{
border:1px solid #00f;
}
table.news td{
border:1px solid #F00;
}
</style>
<style type="text/css">
#t1 td{
border:1px solid #00f;
}
#t2 td{
border:1px solid #F00;
}
</style>