Here is a rundown of the various chicken breeds.
https://www.coopsandcages.com.au/blo...hicken-breeds/
Here you have it, Leghorns and Rhode Island Reds are best for egg production.
http://www.chickens101.com/chicken-breeds.html
Frank Purdue used to advertise that he fed his chickens Marigold petals to make the skin yellow, which it did, and it will also make the egg yoke more yellow. Yellow skin was desirable for broilers as it looked more appealing in the meat case. He didn't raise chickens for eggs but rather for the meat.
North Georgia was a major broiler production area for a long time, I think that has changed now. Arkansas is big in meat production as in Tyson foods. For egg production much of that is done in Ohio, Indiana and New York that I know of. There is a egg producer in Ohio that has over 11 million hens in egg production at one site. Rose Acres in Indiana has over 24 million birds in production but they are spread out over the state. Actually there are major egg producers throughout the US, one producer has over 35 million birds in production. Think about the number of eggs produced every day.
Don't know what you could feed a chicken to affect the color of an egg shell though. Now a Cream Legbar will lay blue, olive or green eggs. As for the color in chicken poop, we used to have fun with non farmers and ask them if they knew what the white was in chicken poop. When they couldn't answer we said "that's chicken poop too"
For a different breed of hen check out a Guinea Hen. Farmers used to keep a small flock of them around as watch dogs. If a stranger would come into the farmyard they would get excited and raise all kinds of noise to alert the farmer. They were good egg layers also but the eggs were smaller.
I am somewhat familiar with chicken production as I worked as a Regional Sales Manager for a major manufacturer of truck bodies/trailers used for feed transportation for 5 years. Many good stories about that.