Why eggs are brown?
It depends on the breed of the chicken. It is a genetic trait. A
rule of thumb is to look at the earlobe of the chicken, and that is
roughly what the eggs will look like. The White Leghorn breed lays
most of the white eggs. The brown eggs come from the Rhode Island
Red, the New Hampshire and the Plymouth Rock.
The reason brown eggs cost more is because the hens are a little
bigger and tend to need more care. Plus there is the urban legend
saying they are healthier, so naturally, stores will charge more
since more people want them. Brown eggs are not any healthier than
white eggs.
Egg colors are not limited to white and brown. There are also
blue and speckled eggs, though they are hard to find in stores.
Those come from the Aracuna breed.