Conditional Dynamic Tab color

All,

Does anyone know how to change the color of a dynamic tab based on another fields value? I got the conditional If -else figured out just not sure how to make the tab change to the color.

$sql = "select * from employees";
$rs = CustomQuery($sql);
while ($data = db_fetch_array($rs)) {

$pageObject->addTab("EmployeeID='".$data["EmployeeID"]."'",
$data["FirstName"], $data["EmployeeID"]);
}

/******************** Not sure how to tie this together

if ($data["FirstName"]= 'John') {
$color="red";
} else {
$color="green";
}
$value="<span style='color: " . $color . "'>" .$value . "</span>";


Thanks in advance