This is what happens when a fabric dye is exposed to extreme lighting conditions. As you can see, some dyes hold up, and some colors wash out.
This is the reason for the military's NIR standards for their uniforms and gear.
Some of the more interesting items that you can see in this series of photos are:
-The 1990's standard-issue woodland camo hat and bdu jacket in the upper left has bleached completely except for the black splotches.
-The hook'n'loop patch on the front of the Flectarn jacket also has poor spectral qualities.
-The Athletic Works woodland camo wicking shirt in the lower right shows it has very little spectral stability as well.
-The scarf bleaches easily.
-The mil-spec OD Boonie hat in the upper right surprisingly also does badly.
I used a blacklight for the Ultraviolet photo, and a mix of 850nm and 940nm LEDs for the Infrared photo. All three taken with a Canon PowerShot A590 IS. Great Camera. (cheap too, I recommend it)
Download for full detail.