What do the green, amber, or red dots beneath cities mean? I was thinking it has something to do with the number of units in the city and whether or not they are fixed. But, this doesn’t seem to match up with what I’m seeing.
A Red dot indicates units present in a city that are besieged or out of supply. A Green dot indicates units are present and supplied. A Blue dot indicates that naval units are present in a harbor. I couldn't find any Amber dots.