What Is the Difference Between White and Gray Hair?

White hair and gray hair come from the same process. A white hair has lost its melanin, the pigment that gives hair its color. A head of hair looks gray when white hairs grow among pigmented ones, and some single hairs sit in between, holding only part of their pigment.

What makes a hair white

Hair color comes from melanin. According to MedlinePlus Genetics, run by the U.S. National Library of Medicine, the amount and type of melanin set a person's natural shade, from black to blond to red. The American Academy of Dermatology (AAD) explains that hair turns gray, or white, when the follicles stop creating melanin.

Inside a graying follicle, the change is measurable. A 2005 review in the Journal of Investigative Dermatology describes a sharp drop in the number of working pigment cells in the hair bulb, the base of the follicle where pigment is made. It also describes trouble passing pigment to the cells that form the hair. With fewer working pigment cells, less melanin reaches the strand. When none reaches it, the new hair grows in white.

Why does a hair with no pigment look white? A 2013 review in the Indian Journal of Dermatology, Venereology and Leprology explains that the white color is an optical effect. Hair is made of keratin, a protein that is naturally pale yellow. Light reflecting off a hair with no pigment hides that pale yellow, so the hair looks white. The white is not a pigment of its own.

Why a head of hair looks gray

For most people who are graying, white hairs grow next to hairs that still have their color. The 2013 review states that this mix of pigmented and white hair is believed to give the appearance of gray.

The mix changes slowly. In a 2012 survey of 4,192 people from several parts of the world, 74 percent of those aged 45 to 65 had some gray hair. On average, the gray covered 27 percent of the head. So on average, in that age range, gray hairs were a minority mixed in with natural color. Our page on when gray hair starts has the full numbers by age and ancestry.

Can a single hair be gray?

Yes. The 2013 review notes that the full range of color, from normal to white, can be seen along a single hair as well as from one hair to the next. A hair can grow in with less pigment than before, or change color partway along its length. The 2005 review adds that pigment cells in graying and white hair bulbs can disappear very quickly.

A 2021 study in eLife measured this directly. Researchers at Columbia University tracked color along single hairs in very fine detail, and saw hairs move from dark to white along their length. In a few cases, hairs turned dark again closer to the root. Because a hair records its growth in order, these color changes could be matched to the weeks when they happened. Our page on how hair gets its color explains why the color is locked in as the hair grows.

Pigmented, gray and white hair compared

	Pigmented hair	Partly pigmented hair	White hair
Melanin in the strand	The person's natural amount	Less than before	Little or none
How it looks	Natural shade	Lighter or grayish	White
What is happening in the follicle	Pigment cells are working	Fewer working pigment cells, or pigment is not passed on well	Pigment cells are no longer supplying melanin

Silver, gray, white: the words people use

Everyday words like silver, gray and white describe how hair looks, not separate kinds of hair. Cleveland Clinic describes aging hair as strands that "start growing in shades of gray, white or silver." Doctors use one word for the whole process: canities, the medical term for graying of the hair.

Why white hair can look yellow

Some people notice that their white hair takes on a yellow tone. That is a separate topic with its own causes. Our post on why gray hair turns yellow covers it, and the guide on yellowing and purple shampoo explains what toning products can and cannot do. Texture is another common question. Our guide on why gray hair feels different covers what changes and what stays the same.

A patch of white hair is different

A single patch of white hair is not ordinary graying. DermNet, a dermatology resource, defines a localized patch of white hairs as poliosis and describes it as a sign rather than a diagnosis. Its listed causes include piebaldism, Waardenburg syndrome and tuberous sclerosis, which are genetic, as well as vitiligo, alopecia areata and halo nevus, a mole with a pale ring around it.

If you notice a white patch, or white hair that appears suddenly, see a doctor. Sudden whitening has its own explanation. A 2013 review of 196 reported cases notes that the hair above the skin has no living cells, and the leading explanation is the rapid loss of pigmented hairs in a form of alopecia areata. Our page on gray hair myths covers this in more detail. This post is general information, not medical advice.

For the full science of graying, from pigment cells to genes and stress, read our guide on why hair turns gray.

LIUMIQ is developing a gradual color product for gray hair. It is not for sale yet. To follow the project, join the waitlist.