“Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power,” the university said, adding that typical commercial white paint gets warmer, not cooler.

Source: Purdue creates whitest paint on Earth, could fight climate change - 10tv.com

Definitely good news. I’m sure you’d have to clean it frequently to always get the best effect, though.