Averages mean very little when it comes to grey hair in women, but studies show that half of the female population will have 50% grey hair by the age of 50. The age most women first notice grey hair is 35. Grey hair in men is first seen a few years earlier at the age of 30. The age you first go grey will depend on your skin tone. Typically, people with paler skin tend to go grey earlier than people with darker skin.