Chicken yolks can vary significantly in appearance. While some are a light yellow, others can be so deep in color that they almost appear red.

But what does it mean? Are egg yolks like lettuce, where a darker color indicates more nutrients?

Fox News Digital consulted with an egg specialist to unravel the mystery.

According to cookbook author and backyard chicken specialist Lisa Steele, in an interview with Fox News Digital, "the hue of a chicken yolk is entirely influenced by the diet of the hen."

Steele, who lives in Maine, is the creator of Fresh Eggs Daily, a website about raising chickens. She is also the author of "The Fresh Eggs Daily Cookbook."

"Foods that are high in xanthophyll and carotene, which are basically pigments called carotenoids, will make nice dark orange egg yolks," she said.

She mentioned that carotene is present in foods that are orange in color, like carrots, mangoes, cantaloupe, and pumpkins.

Xanthophyll is present in green leafy vegetables such as spinach and kale.

However, a deeper-colored egg yolk doesn't necessarily indicate that a chicken is consuming a healthy, organic, or fresh diet. "Still, it is likely to be associated, as the foods containing the pigment are often rich in other nutrients," she explained.

Even so, feed companies and commercial egg farms have discovered workarounds to create a darker egg yolk without these nutrient-dense foods, Steele said.

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According to her, these companies have become savvy and recognized that customers prefer to see that vibrant orange yolk, prompting them to incorporate ingredients like marigold, paprika, sea kelp, corn, and alfalfa to enhance the yolk's color artificially.

To ensure the most nutritious eggs possible, Steele suggests customers look for certain labels on cartons at the grocery store.

According to Steele, chickens that are "pasture-raised" or "free range" usually produce eggs with yolks that are darker and more orange in color. This is largely due to their diet, which primarily includes grasses, weeds, and various plants.

She emphasized that "cage-free" and "pasture-raised" are distinct terms and should not be confused.

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Steele informed Fox News Digital that pasture-raised eggs represent the "gold standard," highlighting that certain "cage-free" chickens might still spend their lives confined within a warehouse.

The eggs from pasture-raised chickens have less cholesterol and more nutrients, Steele said, because of their healthier, more varied diets.

Egg yolks aren't the only items that showcase a variety of colors.

The shells also differ.

Steele stated that, in contrast to yolks, the color of an eggshell does not affect the egg's nutritional content.

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Steele mentioned that the color is "entirely determined by the breed of chicken."

"Certain hens are dyed brown, others are blue, and some have no dye at all."

And that's not an exaggeration.