Sorry für meinen Denkfehler... ;)
$color = "";
while($select = mysql_fetch_row($query)) {
if ($color == "#ffffff") $color = "#c1c1c1";
else $color = "#ffffff";
print "<tr>";
print "<td bgcolor=$color>$select[0]</td>";
print "<td bgcolor=$color>$select[1]</td>";
print "</tr>";
}