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Help! This Milk is a Funny Color: Possible Causes of Colored Milk

Palette with a variety of shades of colors.

I can’t begin to imagine how many calls I’ve had from both parents and professionals who are half-panicked about colored milk. I doubt I’ll be able to lay all of these issues to rest, but I’ll try!

I’ve never read a research study to support my clinical observations, but I’m going out on a limb here anyway. With the exception of the first few days, most colored milk is a funny color because of one of these three situations:

  • Consumption of a food or fluid (highly likely)
  • Consumption of a drug (certainly possible)
  • Pathology (possible, but less likely)

That means that before you toss it out or panic, consider the food and fluid question. In my experience, it’s the most likely explanation.

Red/pink, red/orange, red/brown milk

In the first few days postpartum, definitely, I’d be thinking rusty pipe syndrome postpartum.

Thereafter, I would start asking questions about fruits and vegetables. Beets are famous for making red or pink colored milk. Blackberries and rhubarb are other potential explanations. And there’s probably more I’m forgetting.

Pink milk

Pink colored milk is another thing for which you’ll need to raise some serious questions. Pink milk has been associated with

  • MRSA
  • Serratia
  • Pseudomonas

Nevertheless, the pink discoloration could be attributable to something far less ominous such as the foods listed above.

Orange milk

I admit I get a little worried when I see bright yellow/orange colored milk. Like school-bus yellow orange. The mother may be affected with methicillin-resistant Staphylococcus aureus (MRSA).

But not necessarily.

Studies have been done on milk that is not discolored, yet it tests positive for MRSA. So don’t rely on the color of the milk to feel reassured or worried. Either one.

Meanwhile, imagine me seeing some orange colored milk and starting my whole line of questioning about a possible infection. At the time, I was young and foolish and believed that everything that looked odd must be abnormal, pathologic, and dangerous. Detecting such uneasiness, the mother said:

“By the way, I’m married to a sweet potato farmer.”


Let me be quick to say, however, that sweet potatoes, carrots, pumpkins, or any of those orange vegetables aren’t likely to create as much or as dramatic a discoloration as would an infection.  

A couple of lessons to learn here:

  • Slow down before you go rushing into a worst-case scenario where you scare the blazes off from everyone.
  • Never be afraid to pursue your suspicions. Culturing the milk may be wise and prudent.  

Medications, too, can be a cause of orange milk, like phenazopyridine hydrochloride (Pyridium™ ) or rifampin (Rifadin™).

Here’s another thought to keep in mind. If it turns your urine orange, it will likely turn your milk orange.

Green milk

I can think of one woman who was the self-proclaimed poster child for eating green vegetables. Sure enough, every day, her milk was green. In fact, I don’t know if I ever saw her milk any color other than green.

I can think of another mother who could cheerfully have vied for the title of poster child for eating green vegetables. She never had green milk. Ever. Go figure.

When I see green colored milk, I start asking questions about consumption of vegetables such as spinach, kale, and spirulina.

One time, however, I exhausted all of the “food” possibilities I could think of. Suddenly, a colleague realized it was March 18. She asked the mother what she had had to drink the night before.

Sure enough, you guessed it: green beer!

Any type of dye, of any color, can turn milk a funny color. Green Gatorade™ is famous for turning milk green.   

A big word of warning, however. If the mother has an abscess that has ruptured into the duct, her milk is likely to be green and foul-smelling.

Notice, however, that I said if it has ruptured into the duct. Abscesses are usually in the fatty and connective tissue, but a rupture into the ducts  means the milk should not be offered to the baby. Actually, I doubt the baby would take it.    

Blue milk

Yes, I know where the blueberry farm is, but no, I don’t know the farmer’s wife. But I do know that blueberries, if eaten in sufficient quantities, can turn the milk blue.

Another possibility is something like MiO™ water flavoring. You’ve probably seen the blue one. I can think of one woman who got pumped very blue milk after drinking the blue MiO. Again, this is a dye issue.

Black milk

Decades ago, I had read about the antibiotic minocycline (Minocin™) turning milk black. I had never seen it happen, though, and didn’t give it much thought until one evening when I returned to my office after a long day teaching my in-person review course.

A nurse had left a message only a few minutes before. She reported that her patient had black milk.

I called the nurse and ran down my usual list of questions. I almost skipped asking about the Minocin because I’ve seen it prescribed so infrequently these days.

But sure enough, she said, “Oh yes, she’s been on Minocin for several days now.”

I also heard from a colleague that she encountered a mother who had had black milk for the first several days after giving birth to each of her babies. Most astonishingly, the patient’s mother and sister had had the same experience!

Some concluding thoughts

Like anything else, milk that’s a funny color isn’t necessarily worrisome.

In many or most cases, the food, beverages and medications are likely to explain the discoloration. If so, the milk is perfectly fine to give to the baby. Remember, if the mother hadn’t expressed her milk, you’d be none the wiser about the color.

But you can’t be too cavalier about it, either. The color of the milk might be predictive of pathology.

Have you had or seen oddly colored milk? What kinds of questions did you ask to determine the cause? Share in the comments below!

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  1. Mary T.

    I am 3 years late in seeing this article. I have purchased cow’s milk and it has turned orange when it has gone past it’s expiration date. This is store bought milk. Ofcourse this is concerning to me. I have made homemade yogurt and it does not turn orange. And we know that yogurt is past the expiration date in order for it to become yogurt. I can’t see it being something that the cows are eating, if that were the case I would expect the milk to turn green for grass. So my question is what chemical is being used and why? My mother, back in the old country, milked her own cows, and made everything possible you can from milk. The milk itself and products made from it were never an odd colour.

    • Marie Biancuzzo

      Sorry for the late response. Milk “turns colors”, and sometimes it has been identified what what give is that tint. Other times, it remains a mystery.

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