Hair color is caused by a pigment (melanin) that is produced by the hair follicle. With aging, the follicle produces less melanin.
Review Date 7/12/2018
Updated by: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.