As the blue color in the shell is derived from bile it would seem reasonable that it could be changed with diet.
This is very true! My blue egg color has just changed from diet alone.
My feed store recently started carrying Purina feeds so I decided to switch to their Layena pellets to try them and within a few days I noticed my eggs were all getting bluer- both in my Legbars and Ameraucanas. Nothing else has changed except diet. I was feeding Agways hearty hen before this which I liked and the girls seemed to enjoy but I figured a switch up could be good for them.
Hearty Hen has 18% protein and Layena only has 16% protein so I was planning on going back to Hearty Hen but now I'm not so sure...
Here are the labels side by side for comparison. The only thing I see that's a huge difference besides protein is Layena has a lot of plant protein listed and also has Diatomaceous Earth
