<?
$query = mysql_query("SELECT item FROM table WHERE color = 'red'");

$system_array = array() ;
$i = 0 ;
while ( $row = mysql_fetch_assoc( $query ) )
{
   $system_array[ $i ] = $row[ 'item' ] ;
   $i++ ;
}
$item_list =  implode( ', ', $system_array ) ;
echo $item_list;
?>