My wife bought me a brown AK for my birthday. Sadly, she didn't order it early enough and it arrived 2 weeks after the fact. But brothers let me tell you it was worth the wait.
I think Mike hit the nail on the head with this type of material. It's a happy medium between the black and the putty (I think he calls it khaki now). The pleats are less prone to curling like the black and the material moves much better than the putty.
The first time I wore it was to help move my sister-in-law. One of the appliance deliverymen looked at me and said "Man, let me buy that kilt off you. That's got to be the perfect thing for this heat." He was later heard by my saying that he really needs to get himself one of those kilts.