Regardless of which tracker icon is set, there is a color indication of the tracker status.

Green color of the icon - the tracker regularly sends data with an interval of less than 5 minutes (the tracker is considered to be on)

Yellow color of the icon - the tracker did not send data for 5 minutes

Red color of the icon - the tracker has not sent data for more than 10 minutes (the tracker is considered turned off)

The blue color of the icon is an approximate location (coordinates determined based on cell towers, wi-fi networks, or other alternative methods)

A circle of several colors - the tracker sent a packet without coordinates (Ping packet)
What is a Ping packet is described in detail in this article of our documentation.