On a house you have roof vents and overhang vents. The Idea is to pull air in thru the overhang vents and expell it out the roof vent which is supposed to get rid of moisture.
Not going to paint any covers black but will cover at least one of the hives cover with black plastic this summer. Open up the SBB fully and install a 2" deep vented rim above the outer cover and give it a try.
Not ready just yet to sacrfice a hive to expermint with it in the winter.
My thinking at the moment is during winter one wouldn't want the effect of cold air being drawen into a hive.