what works the best is distance....and sometimes even that can't beat a random encounter like we had this year in the Smokies. We were just lucky he was cool (private property owner).
Next to distance is natural cover/blocks. For me usually thats large thick stands of rhododendron, it would even hide CoolDays bright orange tarp.
Then the pattern. Doesn't matter what color it is if it is a solid block of one color-it will catch the eyes. But whose eyes? Remember the classic red/black plaid by one of the big name wool makers (orvis maybe? filson?) anyway that plaid you and I'd pick out is camo to animals.
Me I like flecktarn but I can't see any cottage ever making a tarp in that pattern!