A little off-topic, but here is an interesting video of a guy trying to create a paint that will radiate more energy than it absorbs so it is cooler than ambient temperature in direct sunlight.
Reading through some of the comments, someone pointed out that the paint may appear cooler to an IR sensor because of the change in emissivity of the surface. I think making a panel that would cool air or water that could be verified with a thermometer would be a good experiment.
At the very end, he is sporting a Michigan shirt.