What does the greenish colour mean?

[Blanchflower]

Hi! I hope someone can help me here. What does the greenish colour at the top of SOME of my cities mean? Some of my cities show a normal colour but others show a greenish colour coming out of the cities! Can someone help me here? Thanks!!

 

[Psimon]

Likely sick; you would be able to see a sick yuck face as well. It's caused by a combination of overcrowding and possibly city improvements related to production, like the Forge, Factory, Coal Plant, etc. Also nearby jungle, floodplains contribute, and so on.

You need to either build some health bonus improvements there, do something about the overcrowding, cut jungles, or even set up some trade with other civs to get some health enhancing items.

 

[Bostock]

It's jungle and flood plains rather than jungle and grasslands that increase unhealth.

"Overcrowding" refers to the number of population points in the city -- it's -1 health per point.

You can see the sources of health and unhealth in your cities by hovering the mouse over the health display near the top of the city screen.

I realize unhealth isn't a word.

 

[Psimon]

Thanks Bostock; corrected.

Addressing the overcrowding, well, is usually counterproductive. The only ways I know of to do it is to whip the people (under Slavery); You can reassign what tiles are worked to either starve (not a good idea) or put them in a stagnant condition, and click the button to avoid growth. Of course, none of those (save whipping) help much if they're already overcrowded.

I usually look to build health-bonus improvements, or, if I can't do that, try to make a few new trades (or cancel a few) to gain some health improving resources.

A related question from me would be, what's the BLUE MIST I often see flowing out of a city? It's temporary. Maybe related to a unit available for promotion there?

 

[Bostock]

Precisely - one or more units there with still-unused promotions. If they're not in a city, then you'll see the mist in that other not-a-city place.