Why are chicken eggshells different colors

There is no better way for a backyard or homestead chicken keeper to add color into their lives than having chickens that lay colored eggs. Think of your kids asking for green-shelled eggs today and tomorrow asking for the blue one. 

Colored chicken eggs are fascinating and one is left to wonder how chickens can produce eggs of different colors. Aren’t chickens and should produce eggs of the same color? Not really. Though it looks like a chicken, walks like a chicken, and clucks like a chicken, eggshell color is specific to different chicken breeds. 

The color of eggshells is a factor in the genes of the chicken. Chicken genes are specific to breeds. Leghorn chickens will give you white eggs, Ameuracana blue eggs, and Orpington eggs with brown-colored shells. This cannot be changed since it is wired in the genetics of the breed. Over time breeders have come up with chicken breeds that lay other colors of eggs. For example, a breeding s rooster and hen from breeds that lay blue eggs and brown eggs produced the Olive Egger breed. This breed lays eggs that have olive green-colored eggshells. 

The good thing about chickens is that you do not need a DNA test to find out what color of eggs they will lay. A look at the ear lobes will give you an idea of the color of eggs. A chicken with white earlobes will give you white eggs. 

What Causes Different Color Egg Shells

Though chickens produce eggs of different colors, depending on the breed. All eggs start equal. White in color. They take an average of 25 hours to form, with the shell taking 20 hours to form. As the egg travels through the oviduct, it gets its eggshell color. This is where the color is determined by the genetics of the chicken breed. 

Chickens that lay colored eggs release different pigments to determine the color of the eggs. Some pigments permeate the eggs shell, giving a uniform color on the outside and inside. 

Other pigments do not get into the inner side of the eggshell, giving the egg one color on the outside and another. color on the inside. 

Olive Green and blue egg from the same chicken, 3 days apart. Sometimes anomalies happen where chickens will lay a different colored egg once in a while. Photo credits: Kelly C.

Some pigments are overlayed over other pigments to give the eggshells a different color. This is in the case of Olive Eggers where a brown pigment is released later in the process to overlay the blue pigment released earlier. This combination leads to the production of an olive green egg. The shade of the olive green eggshell is determined by the intensity of the brown pigment. Darker brown pigments will produce a stronger olive color.

Egg Shell Color and Nutrition. 

Varying eggshell colors come with different color intensities. One might wonder if eggs of a particular color are more nutritious than others. This might be confusing since, in other foods like vegetables, darker green vegetables are said to be more nutritious than light green ones. 

In some countries, white-colored eggs are thought to be more nutritious while in others brown eggs are preference. A study by the University of Illinois had different findings. Eggshell color does not add or take away the nutrients in the egg. Chicken fed with rich nutritious feed will lay more nutritious eggs. 

Egg Shell Colors

The colors of chicken eggshells vary from breed to breed. The main colors are white, brown, blue, green, pink, and speckled eggs. 

The shell is made up of calcium carbonate. This is supplied from the bones of the chicken and the reason laying hens need enough calcium in their feed.

White.

All eggshell colors start out as white. This means if your chickens lay white eggs, no color was added in the egg-making process. It came out as it was at the beginning. 

In countries like the United States of America, there is more demand for white-colored eggs than brown ones. 

White eggs are laid by both heritage and commercial chicken breeds. Heritage chicken breeds include White Leghorn, Andalusian, Polish, Ancona, Egyptian Fayoumis, Hamburg, and California White. Commercial chickens breeds, also known as hybrid chickens, that lay white eggs include Lohmann Brown Classic, Hyline Brown, Brown Plus, Silverbrown, Bovans Brown, Shaver Brown, H & N Brown Nick, British Blacktail, and Lohmann Brown Lite.

Brown.

Brown is the second most popular color in supermarkets in the United States. Some states prefer brown-colored eggs to white. 

Brown-colored eggs have a brown pigment applied to them during egg formation. This is after the shell is formed and is passing through the oviduct. The brown pigment does not penetrate the inner part of the eggshell. This results in the eggshell being brown on the outside and white on the inside. 

The color intensity of the brown color of eggs varies from light brown to dark brown, similar to the color of chocolate. This is influenced primarily by the breed of chicken. Other factors that will influence the intensity and the tone of the eggshell include stress and age. 

Chickens that lay light brown eggs include White Plymouth Rocks, Black Australorps, Barred Plymouth Rocks, Single Comb Rhode Island Whites, Rhode Island Reds, New Hampshires, Welsummers, and Buff Orpingtons

Chickens that lay dark brown (chocolate) eggs include Barnevelder, Maran, Penedesenca, Welsummer, Empordanesa.

Blue.

Blue eggshells are formed when a pigment known as Oocyanin, is applied to the eggshell at the early stages of egg production. Since it is applied earlier in the egg production process, the blue color penetrates the eggshell. This results in the eggshell having a blue color on the inside and outside. 

The intensity and tone of the blue color are influenced by the breed. Stress and age also play a role in the shade of blue of the eggshell. 

Chickens that lay blue eggs include  Ameraucana, the Araucana and the Easter Egger, Cream Legbar, Ice Cream Bar.

Green.

Green-colored eggs resulted from breeding blue egg layers with brown egg layers. This resulted in an eggshell that is green on the outside and blue on the inside. 

After the white eggshell is formed, the blue color is applied at the early stages of formation. The blue pigment penetrates the eggshell, giving it a blue color on the outside and inside. 

It does not end there as a brown color is overlaid on the eggshell in later stages of formation. This gives the eggshell, which is blue at this stage, a green color. Since the brown pigment does not penetrate the eggshell, the eggshell remains blue on the inside. 

Chickens that lay green eggs include Isbar, Silverudd Blue, Favaucana, Ice Cream Bars, Ameraucana, Olive Eggers

Pink.

Pink eggshells come from hens that lay brown eggs that have been bred with hens that lay blue eggs. Extra bloom is applied to the egg, giving it a pinkish tinge. 

The Croad Langshan is the only chicken breed that lay pink eggs. Light Sussex, Mottled Javas, Australorps, Buff Orpingtons, Silkies, and Faverolles lay cream(light brown) eggs with a pinkish tint. Some Easter eggers also lay pink eggs with pink eggshells. 

Chickens Egg Shell Color Chart

Color of EggshellChicken Breeds
White EggsHeritage Chicken Breeds: White Leghorn, Andalusian, Polish, Ancona, Egyptian Fayoumis, Hamburg, and California White.

Commercial Breeds: Lohmann Brown Classic, Hyline Brown, Brown Plus, Silverbrown, Bovans Brown, Shaver Brown, H & N Brown Nick, British Blacktail, and Lohmann Brown Lite.
Brown EggsHeritage Breeds: White Plymouth Rocks, Black Australorps, Barred Plymouth Rocks, Single Comb Rhode Island Whites, Rhode Island Reds, New Hampshires, Welsummers, and Buff Orpingtons
Dark Brown EggsHeritage Breeds: Barnevelder, Maran, Penedesenca, Welsummer, Empordanesa.
Blue EggsHeritage Breeds: Ameraucana, the Araucana and the Easter Egger, Cream Legbar, Ice Cream Bar.
Green EggsHeritage Breeds: Isbar, Silverudd Blue, Favaucana, Ice Cream Bars, Ameraucana, Olive Eggers
Pink EggsHeritage Breeds: Croad Langshan