Difference between Gray and White Hair

Older people with stylish gray hair
Photo: T-Design/Shutterstock
Q: What is the difference between gray hair and white hair?
A: According to scientists, there is actually no such thing as a gray hair. Hair is either a certain color (black, brunette, red or blonde), or it is white. “Gray” hair is a mixture of colored hair and white hair, which is described perfectly by the term “salt and pepper”.
Thus, hair appears progressively more gray as the white hair increases. Hair can also be white at the base/root area as it is growing out, and still be colored at the halfway or end part.
White hair is the product of absence in melanin in the hair. Melanin is the pigmentation in the hair that gives the hair its specific color. Melanin can be categorized in eumelanin and pheomelanin. Pheomelanin is responsible for red and blonde shades, while eumelanin is responsible for darker shades such as black and brown.
People with very little pheomelanin will usually have blonde hair. Blonde people’s hair tends to turn gray and white quicker than those who have naturally dark hair. This is because people with dark hair have more melanin (eumelanin) present in their hair, which causes the hair to keep its color.
Scientists were always under the impression that white hair does not contain any melanin, due to the melanocytes being incapable of producing melanin/color pigmentation, which is caused due to aging or extreme shock/trauma. Yet it has been found that there are some melanocytes present in the papilla of white hair, yet the melanin cannot be transmitted to the hair shafts. The reason for this cannot be distinguished yet.
Imagine the profit that you’d be able to make if you could figure out why the melanin cannot be transmitted to the hair shaft when a person ages. If you could find a way to correct this, you would have the perfect solution for people to keep their natural hair color throughout their lives, without ever going gray and never having to color their hair.
Thus in short, gray hair is really just a mixture of white hair and hair that still has color/melanin in it. As you get older, the number of white hairs increases and the number of colored/pigmented hairs decreases, giving the hair a progressive gray look. When there is no colored/pigmented hair left, you will have completely white hair.
It is interesting to know that there are no salon coloring products that can color your hair gray or white. The stylist will first have to strip all the pigment/melanin from the hair’s structure with bleach or a stripping agent, to get the hair shaft to be a white color. Then the stylist can tone the hair to a gray or silvery white color by mixing artificial pigmentation (salon color) and applying it to the stripped hair shaft.
See also:
Going gray
Gray hair myths
Why and how hair turns gray