Chickens lay different colored eggs because of genetics. Each breed inherits specific pigments that are applied during eggshell formation. Blue eggs receive pigment during shell development, brown eggs receive pigment just before laying, and green or olive eggs form when both pigments combine. Eggshell color does not affect nutrition, taste, or quality.
This article is reviewed for accuracy using poultry science references and breed standards commonly used by hatcheries and poultry specialists.
Chickens are often associated with white or brown eggs, but many breeds lay eggs in a surprising range of colors, including blue, green, olive, pink, cream, and deep chocolate brown. This naturally raises a common question: Why do chickens lay different colored eggs?
The short answer is genetics. Eggshell color is determined by a hen’s breed, not by diet or health. Chickens inherit pigments that are applied during egg formation, which determines whether eggs are white, brown, blue, green, or olive. This guide explains how egg color forms, what colors chickens can lay, and which breeds create a rainbow egg basket.
What color eggs can chickens lay?
Chickens can lay white, cream, brown, blue, green, olive, and pink-tinted eggs, depending on breed. Each hen lays only one base egg color throughout her life, although the shade may lighten slightly over time.
Genetically, there are only two base egg colors: white and blue.
- The blue egg gene is dominant over the white egg gene.
- Brown eggs are created when brown pigment is added to a white egg near the end of shell formation.
Because the pigment is applied externally, brown eggs are white on the inside once cracked. Blue eggs, on the other hand, are blue throughout the shell because the pigment is deposited during shell development. Green and olive eggs are simply blue eggs with a layer of brown pigment added before laying.
Some breeds, such as Marans, lay very dark brown eggs at the beginning of their laying cycle. Over time, egg color may gradually lighten as pigment reserves decrease, which is completely normal.
How egg color forms inside a hen (simple timeline)
Egg color depends on when pigment is applied during egg formation:
- All eggs begin white.
- Blue egg layers apply pigment during shell formation, coloring the shell inside and out.
- Brown egg layers apply pigment in the final hours before laying, coloring only the outside.
- Green or olive eggs form when a blue egg receives a brown pigment overlay.
This timing explains why brown eggs are white inside, while blue eggs remain blue throughout the shell.
Where do colored chicken eggs come from?
The origin of blue eggs can be traced back to South America. In 1914, Dr. Salvador Castello documented a unique chicken breed in Chile that laid blue eggs. These birds were known as Araucanas, derived from Mapuche fowl kept by the indigenous Mapuche people.
From these original birds, three related breeds emerged:
- Araucanas: Rumpless, tufted birds that lay blue eggs. They are typically available only through breeders.
- Ameraucanas: Bearded and muffed birds with tails that lay blue eggs and have defined breed standards.
- Easter Eggers: Mixed-breed chickens carrying the blue egg gene, capable of laying blue, green, or olive eggs.
All blue and green egg-laying chickens today inherit that trait from the original Araucana bloodline.
Dark brown eggs come from European breeds such as Marans, which originated near the port town of Marans in France. These chickens were selectively bred for deep chocolate-colored eggs, a hallmark of the breed. Other breeds, including Welsummers and Penedesenecas, also produce rich brown eggs.
Are different colored eggs healthier?
No. Eggshell color does not affect nutrition. White, brown, blue, and green eggs contain the same nutrients when laid by healthy hens.
Consumer preferences vary by region:
- In the United States, white and brown eggs are most common.
- In Japan, pink-shelled eggs are preferred.
- In the United Kingdom, brown eggs dominate the market.
- In Israel, white eggs are favored.
While shell color does not matter nutritionally, yolk color can change based on diet. Chickens that consume leafy greens or feeds containing marigold petals often produce darker yolks due to carotenoids. However, darker yolks are not more nutritious than lighter ones.
For best egg flavor, it is recommended to avoid feeding chickens strong-smelling foods such as fish, onions, or garlic, as these can affect taste.
Breeds for a rainbow egg basket
If you want a colorful egg collection, choosing the right combination of breeds is key.
- White eggs: Leghorns, Anconas, Dorkings, and other Mediterranean breeds
- Cream or off-white eggs: Polish, Faverolles
- Light brown eggs: Plymouth Rocks, Brahmas, Orpingtons, Sussex, Wyandottes
- Blue eggs: Araucanas, Ameraucanas, Cream Legbars
- Dark brown eggs: Marans, Welsummers, Penedesenecas
Crossing blue egg layers with brown egg layers results in green or olive eggs. Many modern hybrid lines, such as Prairie Bluebells and Whiting True Blues, were developed specifically to produce consistent colored eggs. Check out the Farm Directory to find your favorite breeds. Grab your egg cartons, chick sorting baskets, and go check your nest boxes for those beautiful eggs!
Why egg color can change slightly over time
While a hen will never change her base egg color, small variations can occur.
- Age: Older hens often lay lighter-colored eggs.
- Stress: Heat, predators, or illness can reduce pigment application.
- Laying cycle: Heavy production can temporarily deplete pigment reserves.
These changes affect shade, not the fundamental egg color.
Frequently asked questions about chicken egg colors
Why do chickens lay different colored eggs?
Chickens lay different colored eggs due to genetics passed down by their breed. Eggshell pigments are inherited traits and remain consistent throughout a hen’s life.
Can one chicken lay different colored eggs?
No. A hen will only ever lay one shell color. While egg shade may lighten slightly over time, the base color never changes.
Are blue or green eggs healthier than brown eggs?
No. Eggshell color has no effect on nutrition. All eggs contain the same nutrients when produced by healthy hens.
What breed lays blue eggs?
Araucanas, Ameraucanas, Cream Legbars, and some Easter Eggers lay blue eggs due to a dominant blue egg gene.
What causes green or olive eggs?
Green or olive eggs are produced when a chicken with the blue egg gene also applies brown pigment before laying.
Do darker egg yolks mean healthier eggs?
No. Yolk color reflects diet, not nutritional value. Darker yolks usually come from feeds rich in carotenoids.
Why do brown eggs turn lighter over time?
Some brown egg layers, such as Marans, apply less pigment as the laying cycle progresses, resulting in lighter shells.
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Chicken egg color chart by breed
How to build a rainbow egg basket (simple how-to)
Building a rainbow egg basket is about breed selection, not feeding tricks.
Step 1: Choose at least one white egg layer
Leghorns or Anconas provide consistent white eggs and strong production.
Step 2: Add a brown egg layer
Breeds like Orpingtons or Marans supply light to dark brown eggs.
Step 3: Include a blue egg layer
Ameraucanas or Cream Legbars contribute true blue eggs.
Step 4: Add a green or olive egg layer
Easter Eggers or Olive Eggers complete the color spectrum.
With these four steps, you can naturally collect white, brown, blue, and green eggs from the same flock.
Final thoughts
Chickens lay different colored eggs because of breed-specific genetics, not because of diet, nutrition, or environment. Egg color is purely visual, but it offers a fascinating look into poultry genetics. By choosing the right mix of breeds, you can enjoy a naturally colorful egg basket while knowing every egg offers the same nutritional value.
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