Eeeexcellent, I’m excited for you.

I’ve seen some science channels posting these over the last few years, making coatings that emit radiation in the “atmospheric window” I think it’s called, but have not yet seen proper products on the market. I could be out of date though. Still, I’d question durability, but I suppose it’d be at least no worse than normal materials, right?

You might want to look at metal roofing. White helps and makes sense from a visual standpoint where the base material can only be dyed/painted and not changed, but even painted metal reflects infrared better, which is where the heating energy really exists.