Is there an entity with green colour already? If not would you consider it? Because miners are relatively different in concept and placement compared to other production building.

how does it look?
http://osldgoth.db48x.net/piwigo/_data/i/upload/2017/07/14/20170714223711-2046cf37-xl.png
http://osldgoth.db48x.net/piwigo/_data/i/upload/2017/07/14/20170714223711-ea10c949-xl.png
http://osldgoth.db48x.net/piwigo/_data/i/upload/2017/07/14/20170714223708-93cccd29-xl.png

Might get a while to get used to it, I'm not entirely sure if green is the right color after all, my idea is just generally diverge miners from normal production building because they are fundamentally different. Probably needs other people's opinion to have a good say on this matter.

Maybe miners should have a high contrast, in order to be seen under a variety of ore types