the code to display the date in the table cell would look like this:
<td><?php echo $row_recordsetName['columnName']; ?></td>
you would need to add an if statement to convert the date to a time stamp and compare the current time stamp and add a style if the date has already passed:
<td <?php if(time() >= strtotime($row_recordsetName['columnName'])) { ?>class="grey"<?php } ?>><?php echo $row_recordsetName['columnName']; ?></td>
if you define a css rule as:
<style media="screen" type="text/css">
.grey { background-color:#666; }
</style>
it will turn the cell grey