Why would chickens be blue in the Soviet Union?

Question

A 2017-12-30 NYRB article mentions "blue chickens sold in state grocery stores". An anecdote about life in the Soviet Union also mentions that "[b]lue chickens would sometimes be sold outside" the "regular small 'grocery stores.'"

Why would chickens be blue? Was it due to some sort of chemical treatment?

---

For the benefit of those who think that by "blue" chickens they're referring to chickens with a few feathers that might at a stretch be considered blue, here is the fuller quote from the NYRB article:

Nor would the private markets sell mayonnaise. They’d sell everything else—poultry birds proudly displaying curly yellow fat in their cavities, as if in reproach to the bony and blue chickens sold in state grocery stores.

I imagine that these chickens were plucked in order for one to tell that they had "curly yellow fat" or were "bony".

Answer 1

If a chicken doesn't have much fat, its flesh takes on a bluish-white tinge:

Raw poultry can vary from a bluish-white to yellow. All of these colors are normal and are a direct result of breed, exercise, age, and/or diet. Younger poultry has less fat under the skin, which can cause the bluish cast.

So the chickens sold in state grocery stores were quite lean, in opposition to the chickens with "proud displays [of] curly yellow fat" mentioned in the NYRB quotes.

Answer 2

I do remember that plucked chickens sold in Romania in the '80s had a bluish tinge. Had to do with blood color (like the veins inside the back of your hand) and lack of fat not with skin or feather color.

They were also small, bony (insufficient food) and hard to find (as in hours long waiting line in the store).

Most frequent chicken in the store was without breast or legs - basically good only for soup.

Answer 3

I am not a chicken expert, but just as with other animals or with human, pigmentation may affect not only hair/fur/feather, but skin, too. For example, dogs and pigs generally have big patches of pigmented skin often under their darker fur.

That being said with some googling you can find chickens with eg. black skin (some black chicken from China called Silkie Chicken: wikipage of Silkie ). Blue (or bluish gray ) skin can easily be some local variation of this chicken or a similarly colored breed.