Hair color is the pigmentation of hair follicles due to two types of melanin: eumelanin and pheomelanin. Generally, if more eumelanin is present, the color of the hair is darker; if less eumelanin is present, the hair is lighter. Levels of melanin can vary over time causing a person's hair color to change, and it is possible to have hair follicles of more than one color.
Particular hair colors are associated with ethnic groups. The shades of human hair color are assessed using the Fischer–Saller scale. The Fischer–Saller scale, named after Eugen Fischer and Karl Saller, is used in physical anthropology and medicine to determine the shades of hair color. The scale uses the following designations: A (light blond), B to E (blond), F to L (blond), M to O (dark blond), P to T (brown), U to Y (dark brown/black) and Roman numerals I to IV (red) and V to VI (red blond). See also the Martin–Schultz scale for eye color.
Other articles related to "greyed":
... Permanent color, as the name suggests, permanently colors the hair - however because hair is constantly growing, the color will eventually grow out as new, uncolored hair grows in ... Permanent hair color gives the most flexibility because it can make hair lighter or darker as well as changing tone and color, but there are negatives ...