It's black surface helps reduce temperature
Ahh, I don't think so! Black surfaces
absorb heat - they are most definitely not "a better emitter" of heat!. Hot wing sections increase the disturbance of the boundary layer, and lose (up to 1% of the lift) as a result under the same conditions. (figure from memory of an article on the performance of pylon racers.)
Stealth aircraft (including the SR-71) are painted black because they fly around at night (you are not as stealthy if people can see you.) Training military aircraft are painted in hi-vis paint, operational aircraft are painted in low-vis paint. The decision for what constitutes those standards are probably made by some beancounter who can get a cheap deal of 20,000 litres of "midnight black".
