Hair color is perhaps the most obvious characteristic of hair and it is absolutely unique and different for each one of us. And also our very own hair color is different all the time - it keeps changing gradually as years go by - from almost noncolored yet baby hair at birth to already discolored grey hair at elderly age. Children usually have lighter hair, which gets darker over time. After we get sexually mature natural hair shade remains unchanged. As the body ages, or due to diseases, hereditary and stress factors hair can start to get grey, ie, without pigment. In general natural hair shade depends on racial origin, the hereditary factor and so on. However, in each particular case our natural hair color depends on the quantity of natural hair pigment called melanin in our hair. Specifically hair and skin tones diversity is conditioned upon the presence or absence of pigment, its form and quantity in hair shaft and so on. Range of natural hair color shades ranges from black (very high pigment content) to the silver-white (almost complete lack of pigment). All other natural shades come out of these different pigment component relationships. Presently, 50 different natural hair colors are found, they are  grouped into 10 major groups: 5 groups with a strong selection of pigment (in black, chestnut, brown, red and blond) and 5 groups with a mixed ratio of pigment (light chesnut, dark brown, light brown, dark chestnut, ashy). Ethnic differences in hair color are as obvious as are differences in hair type. Most people in the world have dark hair, though in northern Europe blond hair is the most common. Curiously, however, people with blond hair and/or blue eyes are found even in North Africa and the Middle East.