ทำยังไง ให้ เปนตารางสลับสี เป็นกลุ่ม เช่น ID 1 สีขาว , ID 2 สีเทา , ID 3 ขาว

<style type="text/css">
table.gridtable {
	font-family: verdana,arial,sans-serif;
	font-size:11px;
	color:#333333;
	border-width: 1px;
	border-color: #666666;
	border-collapse: collapse;
}
table.gridtable th {
	border-width: 1px;
	padding: 8px;
	border-style: solid;
	border-color: #666666;
	background-color: #dedede;
}
table.gridtable td {
	border-width: 1px;
	padding: 8px;
	border-style: solid;
	border-color: #666666;
	background-color: #ffffff;
}
</style>
<table width="200" class="gridtable">
  <tr>
    <td>ID</td>
    <td>NAME</td>
  </tr>
<?php
$sqq="select * from tb     order by ID";
$qu=mysql_query($sqq);
//$id = 2; ตัวอย่างค่า id
while($ary=mysql_fetch_array($qu)){
		switch ($id) {
			case '1':$colors="#FFFFFF";break;
			case '2':$colors="#CCCCCC";break;
			case '3':$colors="#FFFFFF";break;
		}	
  ?>
  <tr>
    <td style="background-color:<?=$colors?>"><?=$ary['ID'];?></td>
    <td style="background-color:<?=$colors?>"><?=$ary['NAME'];?></td>
  </tr>
<?
}
?>
</table>

    <style>
      table tr:nth-child(odd){
        background-color: #f1f1f1;
      }
      table tr:nth-child(even){
        background-color: #ffffff;
      }
    </style>

<table width="200" border="1">
  <tr>
    <td>ID</td>
    <td>NAME</td>
  </tr>
<?php
$sqq="select * from tb     order by ID";
$qu=mysql_query($sqq);
while($ary=mysql_fetch_array($qu)){
?>

  <tr bgcolor='<?php echo "#".substr(md5(rand()), 0, 6) ?>'>
    <td><?=$ary['ID'];?></td>
    <td><?=$ary['NAME'];?></td>
  </tr>

<?
}
?>
</table>

<table width="200" border="1">
  <tr>
    <td>ID</td>
    <td>NAME</td>
  </tr>
<?php
$sqq="select * from tb     order by ID";
$qu=mysql_query($sqq);
while($ary=mysql_fetch_array($qu)){
  if($ary['ID'] % 2 == 0){ ?>
  <tr style="background-color:#f1f1f1">
<?php }else{  ?>
  <tr style="background-color:#ffffff">
<?php }?>
    <td><?=$ary['ID'];?></td>
    <td><?=$ary['NAME'];?></td>
  </tr>
<?php } ?>
</table>

<table width="200" border="1">
  <tr>
    <td>ID</td>
    <td>NAME</td>
  </tr>
<?php
function randColor($id){
  static $arrColor = array('','');
  if($arrColor[0] != $id){
    $arrColor[0] = $id;
    $arrColor[1] = "#".substr(md5(rand()), 0, 6);
    return $arrColor[1];
  } else {
    return $arrColor[1];
  }
}
$sqq="select * from tb order by ID";
$qu=mysql_query($sqq);
while($ary=mysql_fetch_array($qu)){
?>

  <tr bgcolor="<?php echo randColor($ary['ID']) ?>">
    <td><?=$ary['ID'];?></td>
    <td><?=$ary['NAME'];?></td>
  </tr>

<?
}
?>
</table>