I've been using a sleeping bag in my deer stand for years. Don't worry about color, I'd worry more about noise. The one I use is a cheap bag from years ago. It's a real soft nylon that's quiet when I move around in it. You'll be surprised how much warmer you'll stay. My hunting buddies used to laugh at me, but I could stay on stand hours longer than they could. I always carry several handwarmers that when it's really cold, I open and just drop down in the bag for additional warmth. It's a great idea, give it a try!