Breast Milk Colours: Why Does Breast Milk Change Colour?

August 27, 2023

Breast milk doesn't always look the same.

It may appear yellow, creamy white, bluish or occasionally have a pink or reddish tinge. Seeing an unexpected colour can be surprising — particularly when you're expressing milk and can see it clearly in a bottle.

Many changes in breast milk colour can be normal. Others, particularly when accompanied by breast pain, cracked or bleeding nipples, fever or feeling unwell, are worth discussing with a healthcare professional.

So what can different breast milk colours mean?

Why Does Breast Milk Change Colour?

Breast milk is not a completely uniform liquid.

Its composition changes as breastfeeding becomes established and continues to adapt over time. What you eat, small amounts of blood and other factors can also affect its appearance.

Colour alone therefore doesn't tell you everything about the nutritional quality of your milk.

Yellow Breast Milk

One of the first colours you may notice is yellow or golden.

During the first few days after birth, the breasts produce colostrum. This early milk is usually thicker and often more yellow than mature breast milk.

As milk production changes over the following days, its appearance usually changes too.

Yellowish breast milk isn't restricted to the first few days, however, and variations in colour can occur later as well.

White or Bluish Breast Milk

Mature breast milk is commonly white, creamy or slightly bluish.

You may also notice that expressed milk doesn't look identical throughout the day or from one expression to another.

Older descriptions of breastfeeding often divide a feed very neatly into watery “foremilk” at the beginning and fatty “hindmilk” at the end. In reality, milk composition changes progressively during a feed rather than switching abruptly from one type of milk to another.

So a thinner or slightly bluish appearance isn't automatically a sign that your milk is inadequate.

Can Food Change the Colour of Breast Milk?

Sometimes.

Pigments from strongly coloured foods — and occasionally food colouring — can affect the appearance of breast milk.

That means an unusual colour doesn't necessarily mean there's something wrong.

If the change is temporary and you and your baby are otherwise well, think about whether you've recently eaten or drunk something strongly coloured.

If you're concerned or the change persists, ask your midwife, health visitor or GP for advice.

Green Breast Milk

Breast milk can occasionally have a greenish appearance.

Diet may be one explanation, particularly strongly coloured green foods or food colourings.

Again, colour on its own doesn't necessarily indicate a problem.

If you're worried about a persistent change, particularly if you have other breast or nipple symptoms, seek professional advice.

Pink or Red Breast Milk

Pink, rust-coloured or red-tinged breast milk can sometimes indicate that a small amount of blood is present.

One possible cause is a cracked or bleeding nipple.

Nipple pain and damage are often associated with difficulties with positioning or attachment. The NHS recommends getting help from a midwife, health visitor or breastfeeding supporter if nipples hurt at every feed or become cracked or bleed.

Our guide to Breastfeeding: Is There a Right or Wrong Way? explains positioning, attachment and what to do about sore or cracked nipples.

Breastfeeding: Is There a Right or Wrong Way?

What Is Rusty Pipe Syndrome?

You may come across the term “rusty pipe syndrome”, particularly when searching online for reddish or brown breast milk.

It describes blood-stained milk that can occur around the beginning of breastfeeding, thought to be associated with changes in breast tissue and increased blood flow during pregnancy and early lactation.

However, don't assume that blood in breast milk must be rusty pipe syndrome.

There are other possible explanations for blood-stained milk, including nipple damage and breast problems, so unexplained or persistent bleeding should be discussed with your midwife, health visitor or GP.

When Should You Ask for Medical Advice?

Seek advice if you're concerned about an unexplained or persistent change in your breast milk, particularly if it occurs alongside:

cracked or bleeding nipples
persistent nipple or breast pain
a breast that becomes hot, swollen or painful
a breast lump or hard area
fever, chills or flu-like symptoms
feeling generally unwell

These symptoms can occur with breastfeeding problems including mastitis. The NHS advises contacting your GP if mastitis symptoms don't improve within 12 to 24 hours of treating them at home, or sooner if you feel worse.

If breastfeeding itself is painful, don't simply put up with it. Getting positioning and attachment checked early can help identify one of the most common causes of sore and cracked nipples.

Does Breast Milk Colour Affect Its Nutritional Value?

A difference in colour doesn't automatically mean that breast milk is less nutritious.

Breast milk contains fats, proteins, carbohydrates, vitamins and minerals as well as immune components, and its composition naturally changes over time.

We've explored that subject separately in our guide:

Breast Milk and Its Nutritional Benefits: What Does Your Baby Need?

Breast Milk Is Naturally Variable

Perhaps the most reassuring thing to remember is that breast milk doesn't have to look identical every time.

Yellow, creamy, white and slightly bluish milk can all occur during breastfeeding, and other temporary colour changes may sometimes relate to diet.

What matters more is the wider picture.

If you have pain, nipple damage, fever, breast inflammation, persistent blood in your milk or simply feel that something isn't right, ask for professional advice rather than trying to diagnose the cause from colour alone.