In the bottom center of your screen is a circle which displays the icon of the currently selected thing, be it a town, unit, etc. Around the outside of the picture there is a colored ring (sometimes). Last night my Sov had the right half all blue, but the left half was empty/missing. My town had a ring that went from the bottom up and around to about the "1 o'clock" position, and it was red, blue, green and yellow...
I thought it might be a mana/health indicator, but you already have one of those so it would be redundant. And the multi-colored city one has me completely baffled. Anyone know what it is supposed to mean?
And yes, as a matter of fact I did read the manual.
No help from the tooltips either.
-Sal