Google Calendar can´t get ColorId - php

Question

Anyone know how to get the colorId from google calendar events? I search a lot on web for that and I didn´t find anything that works. I need help.
My code works good but regarding the colorId always receive NULL.
I know we have the $cal->colors->get() method but it's not quite what I want. I want the colors of each the events.
Here is my code:
$client = new Google_Client();
$client->setApplicationName("Ware");
$client->setDeveloperKey('CalendarKey');
$cal = new Google_Service_Calendar($client);
$params = array(
'singleEvents' => true,
'orderBy' => 'startTime'
);
$events = $cal->events->listEvents($calendarId, $params);
$calTimeZone = $events->timeZone;
$events = $cal->events->instances($calendarId, "eventId");
date_default_timezone_set($calTimeZone);
$jsonEvents = json_encode($events->getItems());
$outerArray = array();
$innerArray = array();
foreach ($events->getItems() as $event) {
$date = $event->start->date;
if (!isset($date)) {
$date = $event->start->dateTime;
}
$endDate = $event->end->dateTime;
if (!isset($endDate)) {
$endDate = $event->end->date;
}
$array = array(
"title" => $event->summary,
"description" => $event->description,
"id" => $event->id,
"location" => $event->location,
"start" => $date,
"end" => $endDate,
"colorId" => $event->colorId
);
array_push($outerArray, $array);
}
echo json_encode($outerArray);
The "colorId" => $event->colorId is always NULL.
Public calendar is ON and I have the rights "Make changes and manage sharing".
How can fix that help?
Thanks