I don't know anything about military concerns, but when I wanted some new camo for scenario paintball, I did my research and settled on Multicam.  Even in scenario most people don't bother with any camo, just dress in black and brown, but I decided to take any advantage I can get... it can be hard being mid 30s playing against teens and 20s 

 .  
Anyways, the main thing I learned in my research that I didn't know before is that black is actually a bad color to have in a camo pattern.  Its extremely rare to see black in nature and it actually sticks out more than you'd think.  Most of the non-Multicam patterns available for sale have black in the pattern and the lack of black is one of the things that makes Multicam effective.
There was a really good wiki page that I saw before but now I can only find the generic one with the XBox controller guy.