Originally Posted by
Carbonfiberboy
There's a fabric treatment called "coldblack."
https://www.runnersworld.com/gear/a2...-does-it-work/
We were tandeming (144 team age) up a long hot event climb when we caught(!) a slim, fit-looking rider completely covered in black. He wasn't doing well and was sagged off the course. We guessed he was a victim of this hype.
I prefer skin-tight light colored technical fabrics for riding in the heat.
There is even more of a kernel to truth that that one than the case I saw.
We were on a hot ride in the Antelope Valley, and one of the guys was wearing an all black kit. I asked him ... WTF ... its 100F out here ... why the HELL would you be wearing black?
He assured me it was cooler than white, and told me to "Look it up."
I don't have to look it up to know that is nonsense. And if I wasn't smart enough to know why it is nonsense a simple experiment is all it takes to prove it.
Here is the kernel of truth. Black is hotter in sunshine because the radiant energy of the sun is absorbed by the black color instead of being reflected. But take the change of energy from light wavelengths to heat wavelengths out of the equation (e.g. by taking the object out of the sunshine) and black is a color that is best for heat transfer. That is why heat sinks are typically black. It still doesn't make sense when the outside temp is more than body temp, though ... even in darkness.