Pretty sick. I'd wear them both. I guess if I had to pick I would go with the gray pants. As a general rule I try to avoid black in Georgia though. Anything I can do to keep some heat off of me i'm doing it.
I don't know........The quality of the pants, has more to do with the heat than the color in my experience. I've worn black that breathed well and were very comfortable and I've worn gray that were poor quality and hot as ****.