Free Range in relation to eggs does NOT mean what you think it does!
http://www.mirror.co.uk/news/uk-news/horrifying-truth-brutal-life-free-7634201
The ONLY difference, apart from the price ,between 'free range' and battery eggs is that 'free range are slightly less packed on the the perches so that they can move a few steps. They ARE NOT kept in a nice field with a hen house to retire to at night as most people think!
To produce eggs in the conditions that most people think of as 'Free Range' would put the price up into the 'luxury' range , they do not have more nutrition either or less cholesterol! The colour of an egg yolk is down to the additives in the food , you can buy food that produces egg yolks from almost white to deep red / orange.
There is a farm near me where the chickens run around a large field and have a hen house at night, the eggs are £6.85 a box of 6 and they can't keep pace with demand. That's the sort of price you have to pay for really 'free to roam' hens eggs.