hi chicken farmer the paradox behind is ,the color of the yolk doesn’t indicate the egg’s nutritional value. whether it’s orange or pale yellow, yolks can contain vital nutrients such as protein, vitamins, and minerals.
Not really diet. It’s all about genetics and the type of hen breed. I agree that free-range hens have a different diet, but it is not necessarily as nutritious or more nutritious as caged hens.
I received eggs from the “best clucking” hens on Long Island from a colleague. Her “girls,” as she puts it. I made a lemon pound cake with a couple of eggs. The cake was a beautiful yellow color thanks to the eggs. Eggs from the store seem so little in comparison. 
next time you crack open an egg, you can use the yolk color as a clue to the hen’s diet, but remember, both orange and pale yolks can be delicious and nutritious!