The last couple of whole chickens I've bought have turned out, after cooking, to have lime-green patches in the meat next to the breast bone. They were both "free range", organic chickens. There was no weird odor, and the texture looked the same as the normal meat. We didn't eat it, of course.
Turns out, this is a common occurrence and is called "Deep Pectoral Myopathy" or "Green Muscle Disease". It's caused when the bird is still alive, and develops muscle tears due to excessive wing flapping, or rough handling, or due to poor circulation in birds that are bred for huge breasts.
Fascinating.
And disgusting!

But you may like it in a tree. Try it! Try it! And you’ll see — try it and you’ll see, you see.
(“I do not like it anyway — I do not like it, TMK”)
My guess is that they’re buying a new breed for meat production, instead of one of the older breeds… as you said.
Hope you took some pix for future use as “Monday Green Chicken Blogging.”
i wish i did. it really was lime green.
first time it happened, i had cooked the chicken the “beer can chicken” way, and i assumed the green was from some kind of funky aluminum reaction or burnt paint. it did not look organic.
See what you get for buying those free-range chickens? If they had been forced to live their whole life in a small cage, they would never have flapped those wings.