While white reflects more wavelengths of light, the authors seem to have no consideration to what results from that reflected light in the immediate local sense in terms of the temperature of the air the light is being reflected into.
While white does reflect the most light, that reflection alone must be considered.
Black – the color that absorbs all visible wavelengths of light – attracts the most heat, followed by violet, indigo, blue, green, yellow, orange and red, in descending order. So, next to white, red absorbs less light, compared to all the other colors.
Now imagine in a very hot place and how it will look, to the human eye, to walk down a street at noon with all the houses painted ultra white. Talk about needing sun glasses!!!!
Why not look at what people do who have high heat and lots of sun on most days. In Morocco a color used often on the outside of buildings is a sort of dull red, like the red of red stones in Sedona Arizona. I think the Moroccans know what they are doing.
Red is also, historically, the cheapest color dye, because there were lots of sources.
The reason the Roman legions word red uniforms was simply: red was the cheapest color to dye their uniforms.
Does the article not say that it emits infrared heat? If that is the case, imagine how nice it would be to have a lot less mosquitoes and gnats and other bugs in the immediate area around your house as well.
But, yeah... In MN (not to mention several other northern states) you would have a fairly high heat bill.