I have a bunch of cornish X that are 4 weeks old. Last week I had a bird whose skin was a deep red...almost purple. He was sitting around with eyes closed. I decided he was about to kick the bucket so we brought him in and had a delicious meal of chicken the next night. I thought I was home free with only a couple of weeks left. I had another whose skin was deepening in color but showed no particular sign of distress. I thought I had a few more days. This morning he was dead on his back and someone had obviously used him as a pillow because he was about as flat as a fat bird can get. Moral of the story: If your meat bird starts getting a darker hew than his flock mates, consider having chicken that night or you may not get to eat him at all.