[DanBC]

Ah, those are for the shell. I'm talking about the yolk.

http://blog.chickenwaterer.com/2013/03/influencing-egg-yolk-...

The shell appears to be genetic: http://msue.anr.msu.edu/news/why_are_chicken_eggs_different_...

[ricksplat]

Yeah I wasn't talking about that. Was talking about those creepy paper-white eggs you get stateside.