Why are some eggs brown and some white?

The color of an eggshell is determined primarily by the breed of the hen that laid it. This trait is genetic: hens with white earlobes typically lay white eggs, and those with red earlobes usually produce brown eggs.

Diet and environment can influence the shade of the shell but not its fundamental color. A nutrient-rich diet may deepen the vibrancy of the shell, and factors such as living conditions or stress can also affect its appearance. Still, these factors won’t turn a white egg brown or vice versa—the basic color remains fixed by genetics. Despite some common misconceptions, brown and white eggs provide the same nutritional profile.