The color of the yolk depends on where the egg comes from
Free Range Eggs – Type #1
The darker the yolk , the higher the nutrient content 
. This is generally due to the healthier and more varied diet of free-range hens, which includes not only corn and grains, but also insects and vegetables. Pasture eggs are the most nutritious of the three types 
.
Caged Eggs – Type #2
A diet based on wheat and barley makes the yolks of caged eggs lighter . 
It is the least nutritious of the three types.
Most eggs in supermarkets come from factory farms 
, where the chickens are fed almost exclusively grains. While not harmful, these eggs provide fewer nutrients than free-range eggs.
Free-Range Eggs – Type #3
Free-range eggs
