Doesn't yolk colour depend on the type of chicken and the feed they have? There are additives u can put in to enhance yolk colour (I think paprika is one of them?) but I've never bothered. The chickens that produce the store eggs are pumped with stuff to make their eggs more "attractive" which is why their eggs are like that but it doesn't mean their eggs are good for you.
I think you will find by far that your home grown eggs will be much tastier even without the flashy yolk!!! Enjoy your eggs.
I read a post on here about that but can't remember exactly what it said but something about the chickens eating more bugs and being healthier resulting in getting extra vitamins and the chemicals caused the yolks to be a darker yellow. You should be able to do a search on it.
Backyard chickens generally have access to greens (in the form of grasses and leftover kitchen veggies) and corn.
The dark greens in particular are full of beta carotene. Beta carotene makes for a richer, darker orange yolk.
I free range my flock. In a recent study by Mother Earth News, eggs from free range chickens have 7 times more beta carotene, as well as 1/3 less cholesterol and less saturated fat than store bought eggs.
If you want to read the study, you can do so at www.motherearthnews.com
Ooo...watermelon. They love that. I gave them a watermelon rind as an experiment that other day, they devoured it. Today I gave them canteloupe rinds, I don't think they left anything of that. All the vegetation is what makes their yolks more bright yellow, and thus full of more vitamins for you and I to eat!