A green flag indicates that the agent was within 20 meters distance from the address. An orange flag indicates that the agent was between 20m-50m distance from the address location. A red flag indicates that the agent was more than 50m away from the address.
But note that this distance is measured from the point of the address, so orange or red may not always mean that it was improper. (Ex. If agent was at a corner of the land while distance is measured from the other corner, flag maybe orange or red). So it is important to click on the flag and see the distance shown in the details.