They're pretty much the only reason we get out of bed on the weekends - nothing beats (excuse the pun) an eggcellent brunch. BUT turns out eggs are so much more interesting than their deliciousness!
It turns out that the colour of an egg yolk depends on what the hen has been fed, but it isn't necessarily an indicator of how fresh/healthy/tasty the egg is.
What actually causes the colour of the yolk are carotenoids (yellow or orange coloured pigments in food) like carotene, lycopene and xanthophyll. These are found in foods like carrots, corn, dandelions, marigolds, paprika, pumpkin, tomatoes, and leafy greens.
So yes, free-range chickens do normally produce darker coloured orange yolks, because they're obviously fed a better, more varied diet. BUT commercially raised chickens can also produce bright coloured yolks - they just have to be given some corn or other cheap yellow ingredients with their feed.
Fun fact: the pigments actually determine the colour of the hens' feet and beaks as well, because excess pigment not layed in eggs is stored here.
Our minds are actually blown. You're welcome for your daily dose of #science.
Moral of the story is, eggs are delicious no matter what the colour.