I paint the calipers on all my vehicles. A rattle can of high-temp paint flat black. I re-touch it up when ever I do a brake job. It helps keep the rust at bay. I also paint the brake rotors (masking off the friction surface). This keeps rust from flaking the rotors away from inside the venting. For more bling - I have also used both the eastwood kit as well as powder. I like powder best.

BTW, just a few things from my experience:
Rust is by far a better insulator of thermal transfer than painted metal.
Dot 3 brake fluid is hydroscopic and will boil as low as 250F when it has absorbed enough moisture from the air (at about 7% by volume).
Standard brake seals melt at 250F

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me