At a Glance

Q: What color should breast milk be?
A: Breast milk can be yellow, white, blue, or green. Color changes are usually normal and safe for your baby.

• Green milk often comes from leafy vegetables.
• Pink or red milk may indicate blood.
• Learn when to call a lactation consultant.

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Breast milk is remarkably precise for newborns’ needs—so much so it’s far from being fully replicated, let alone fully understood. Experts even say it deserves more study.

With its finely-tuned recipe of fats, enzymes, and antibodies, breast milk is something of a natural marvel—just ask Molly Bowman, a maternity nurse and internationally board-certified lactation consultant (IBCLC) with Kettering Health First Steps.

“I always say to new moms, ‘Breast milk is a living organism! It’s living and gives life. Breast milk is an amazing, tailored diet for that mother’s baby.’”

Incredible as it is, breast milk can get new nursing parents anxious. As a lactation consultant, Molly helps them through concerns and questions, from milk supply scares, fat-calorie concerns, to the confusion of

“Why is my breast milk a different color” 

Breast milk comes in many colors—yellow, white, blue, green, pink, or red—depending on diet, medications, and breast health. Black or gray milk is rare and should be discussed with a doctor or lactation consultant. Molly explains further.

What color “should” it be?

We often think of breast milk as white. But Molly explains that no hue or color is “normal.” A lot of factors change the appearance of your breast milk, including

• Your stage of breastfeeding 
• Your diet
• Medications you take
• Breast health (such as cracked nipples or enlarged blood capillaries)

Rarely will a certain color mean you should stop feeding your baby your breast milk. “It’s going to be extremely rare for us to say, ‘Don’t give your baby the milk.’” Molly says.

Even so, seeing your breast milk become blue or green or red can be unsettling. Molly clarifies what colors you could see and what they mean.  

What colors are normal?

In the weeks after giving birth, you can expect changes in breast milk’s volume, composition, and color.

Yellow: In the first few days, your body produces colostrum, often called “liquid gold.” This nutrient-packed early milk often appears yellow, especially when frozen. Its color comes from the high levels of antibodies and carotenoids (the compound that makes carrots orange). The body turns carotenoids into vitamin A, which babies have very little of in utero. 

Breast milk may also turn yellow if you’re breastfeeding your baby when they’re sick. The baby’s saliva actually triggers the nursing parent’s immune system to create more antibodies, giving it a yellow hue. 

White: As colostrum transitions into mature milk, it becomes creamier and appears whiter. This thicker, calorie-rich hindmilk is high in fat, helping babies grow and develop. Don’t fret if your hindmilk never looks completely white. Transitional milk has different hues. 

Blue: At the start of a pump session, you may notice a bluish tint in the foremilk, the milk pumped before the fattier hindmilk. Foremilk is lower in fat and has more sugar, helping quench your baby’s thirst before they consume the richer hindmilk. You may see blueish milk separating and floating on the fattier milk in a bottle.

Whey protein in high amounts can also make breast milk appear blue. Blue breast milk is safe for your baby. 

Green: Green veggies like spinach and kale, full of chlorophyll, can give your milk a greenish tint. As can some green food dyes. It may seem odd, but it’s safe for your baby.

Occasionally, Molly says, green milk may signal you’re getting sick. Even then, it’s no cause for panic. You can still give it to your baby since breast milk does not transfer most illnesses.

What colors should you look for?

Most breast milk colors are harmless. But some may call for extra attention if they last more than a few days.

Pink, Red, or Brown: Blood in your milk will often cause it to appear red, light pink, or even brown. Cracked nipples or benign growths in milk ducts, called papillomas, can cause small amounts of blood to enter the milk. 

A brown tint may come from old blood entering the milk, sometimes called “rusty pipe syndrome.” This affects around .01% of nursing parents, and often means blood leaked from expanding blood capillaries in the breast to accommodate more milk.

Pink like Pepto-Bismol^®: Thicker pink milk could indicate a bacterial infection called serratia marcescens, which can be harmful if untreated. This, too, is rare. After nearly two decades as a maternity nurse and lactation consultant, Molly has seen this one time.

Black or gray: While uncommon, medication—particularly an antibiotic called Minocycline—can cause breast milk to appear black. Gray milk, again rare, could mean a breast infection or a clogged duct. 

When to call a lactation consultant

Seeing your breast milk change color is scary. But there’s typically no reason to stop feeding your baby your milk. “There are so many instances where moms are told they can’t give their breast milk,” Molly says. “But they can.” 

Call First Steps, who will work closely with your OB-GYN, for a consultation if 

• Red or pink milk lasts for more than a few days. 
• Brown milk continues, which might be mastitis (a breast infection).
• You notice black or gray milk.

Or, Molly says, call whenever you feel concerned. 

First Steps is also a dispensary for pasteurized human donor breast milk, should you be encouraged to pause feeding your baby your breast milk. It first requires a prescription from your baby’s pediatrician, and then a First Steps lactation consultant will help evaluate if donor milk is best. 

Every new parent has questions, especially if you’re nursing your baby. But with support from lactation consultants like Molly, nursing parents can stay confident and keep their babies nourished, no matter their breast milk’s color.

Call to schedule with a First Steps lactation consultant at (937) 401-6881.

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