I live in South Africa and the yolks of the eggs my wife and I buy are absolutely not nearly white. It may differ by supermarket though, I generally shop at Woo

I live in South Africa and the yolks of the eggs my wife and I buy are absolutely not nearly white. It may differ by supermarket though, I generally shop at Woolworths which markets itself as having the best quality food, while also charging extra as a result. Otherwise, perhaps it's only something which tends to occur with chickens grown by people for themselves in rural areas?