It's a bit ridiculous that there are literally ZERO browns or earth colored clothing for the insurgents, and the only green in their entire collection is LIME green, because fuck...we wouldn't want to blend in now would we. They even made sure to keep the stone colored headscarves and shirts to a minimum. Hell, they even took out most of the blacks...even though those would stick out on these day maps. Apparently the devs think Afghanis and Iraqis wear nothing but brightly colored track-suits and ridiculously gaudy eyewear.
I noticed this too. ISIS the most current and recent enemy overseas with the US wore a great deal of black. It was one of their main themes. But they havent finished the game and also said they would add more customizations. This was addressed a little while back. I wouldnt worry too much yet about this particular issue though it is a bit if a tactical disadvantage.