I don't remember if I mentioned this on this post before, but I fed alfalfa hay to my chickens. I had a hay feeder that would hold one flake of hay. The hens would pick at it. They liked the hay and if nothing else it kept them busy and kept them from getting bored. Bored chickens are prone to...
For orange yolks feed greens. I used to put a flake of alfalfa in a hay rack in the chicken coop. Chickens went nuts for it and it kept them busy if nothing else.