That's a trick answer right? I didn't get the bus with the option for the altered set of universal laws of thermodynamics. How much did that cost?
It's all about the photons.
Even your radiant heat is photons in the non visible Infra red range.
Painting it white is a bad term. Painting it reflective is a better color for reducing thermal load. You can actiaully paint things black and have them more reflective (cooler) than white. It is a function of what's in the paint and usually what's important is what you can't see. Most of the heat action is in the invisible ranges.