What makes eggs different colors?

At Monnett Farms, we raise chickens that lay white, brown and blue eggs. One of the most common questions we hear is “why do the eggs come in different colors?” Basically, it comes down to genetics. Some chicken breeds lay brown eggs, some white and some blue. But that doesn’t really answer the question, so we went on the hunt to learn more.

Monnett Farms chickens produce white, brown and blue colored eggs.
Monnett Farms chickens produce white, brown and blue colored eggs.

One answer you’ll read is that the color of the feathers indicates the color of the egg shell. While there may be some loose correlation, it certainly isn’t true that white feathers mean white eggs and brown feathers mean brown eggs.

Monnett Farms Barred Rock Chickens lay brown eggs
Our Barred Rock Chickens have black and white feathers and lay brown eggs.

Monnett Farms Brahma Chickens lay brown eggs.
We also had a Brahma Chicken with white feathers who laid brown eggs.

Monnett Farms Buff Laced Polish Chicken lays white eggs.
The Buff Laced Polish Chickens have light brown feathers and produce white eggs.

Monnett Farms "Easter Eggers" Ameraucana Chickens lay blue-green eggs
Ameraucana Chickens, also known as “Easter Eggers” have dark brown feathers and produce blue-green eggs.

Chickens Have Earlobes?

More so than feather color, it is actually the color of the earlobes — sounds silly, but most chickens have earlobes — that will indicate shell color. Chickens with white earlobes generally lay white eggs, while chicken with red earlobes lay brown eggs.

Photo showing chicken earlobes by Monnett Farms

There are some indications that there may also be a correlation between the origin of the species and the egg shell color. Mostly speaking, chickens of Asian descent lay brown eggs, Mediterranean chickens lay white eggs and South American chickens lay blue/green eggs.

The Science Behind Shell Color

How egg shells gets their color involves a biology and chemistry lesson, but we’ll try and keep things light here. It takes 26 hours for a hen to produce an egg. Twenty of those hours are required to form the shell. Near the end of this process, some hens will release a pigment that colors the shell.

These pigments are called porphyrins and they influence color in nearly everything from plants to human blood. Concentrations of protoporphyrin result in brown eggs, while biliverdin will produce a blue or green hued egg.

Interestingly enough, a study was recently published by the University of Nottingham School of Biology that illuminated the origin of the blue-green eggs. In the study, researchers found that an ancient virus in native South American chickens resulted in a genetic mutation that triggered an accumulation of biliverdin, causing the chickens to produce blue/green eggs.

An Egg is An Egg

So, what do the different egg colors mean? Well, nothing.

Aside from the fact that their shells are different colors, all eggs are virtually the same. There is a greater difference in eggs based on the chicken’s diet and how it was raised.

At Monnett Farms, we raise our egg laying chickens on pasture, which means they forage for grasses and bugs. Because they cannot meet their daily nutritional requirements from forage alone, we supplement with feed from a local Amish mill.

Learn more about Monnett Farms Pastured Poultry and find out how you can buy our farm fresh eggs.