A good part of my consulting work has to do with egg layer production. As my clients come from distinct parts of the world, I cannot but make a very striking observation when it comes to eggshell color. There are markets, such as in the U.S., where white eggs are virtually the only eggs available. In others, such as in my home country, brown eggs are everywhere. Although it is well established that white eggs cost less to produce and they have the exact same nutritive value, brown eggs continue to be produced, especially for the fresh egg market. Why is that?
Many reasons, but mainly because brown eggs are perceived as closer to "farm" eggs and they can be larger. Being inside the industry, and even having a Ph.D. on nutrition, I still prefer brown eggs. Why? I know they are no different than white eggs, but when it comes to an omelet I limit myself to only eight eggs, nowadays; so, I go for the largest possible eight eggs!
More seriously, though, there is a real problem when a producer of eggs switches from white to brown layer genetics. This is the case for some customers of mine who went from cages to cage-free egg production when cages were banned in the EU. As some brown genetics are considered more robust than many white layers, the brown ones were chosen as a safer bet while the transition was made. In addition, in some countries, cage-free production has been associated with open-range production, and for that consumers expected brown eggs, hence another reason for the switch.
As a nutritionist, my role has been to re-educate my customers to handle a different bird, which required more feed and a different calcium management system as larger eggs do not cause the hen to produce more eggshell; she just spreads available material thinner. Bottom line, brown egg layers have advantages but also they require different feeding management.