I know light colors are much better for rescue, bugs and warmer weather however, the darker colors dry faster out in the sun faster and are better for colder environment and hiding from people hunting you but it is very hot in warm climates and mosquito love you. I wear light cloths when traveling and have all black cloths in a waterproof bag in case I get wet.

The advantage of the black (for back up) is for quick warmth and drying of cloths faster. Hypothermia is a greater concern than the heatstroke for the back up cloths only. Both will kill you fast and that's why I wear the light cloths for traveling and black for emergencys. Every environment is different and this setup applies to my environment.