Red : When tracker is placed in the Hub it will light up red indicating that the battery is low and that it's charging.
White: The tracker will flash white three times when the reset button has been activated on the tracker.
No light: When tracker is charged and put on dog's collar, it will not have any light. The tracker is designed to minimise any disturbance to you and your dog. You will get a notification on your phone if the tracker is running low on battery.