Yes you can change it. but in api 22 and above, using NotificationCompat.Builder and setColorized(true) :
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context, context.getPackageName())
.setContentTitle(title)
.setContentText(message)
.setSmallIcon(icon, level)
.setLargeIcon(largeIcon)
.setContentIntent(intent)
.setColorized(true)
.setDefaults(0)
.setCategory(Notification.CATEGORY_SERVICE)
.setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
.setPriority(NotificationCompat.PRIORITY_HIGH);