|The categorization of skin style is known as the Fitzpatrick skin type (or photo type). It depends on the quantity of melanin pigment present in the skin. This melanin quantity is determined by constitutional colour (like brown, white or black skin) and the effect of contact to ultraviolet radiation (termed as tanning). White or pale coloured skin burns simply and tans gradually and poorly. This type of skin requires more protection against sun exposure. People who had dark skin from the birth time get less skin burns problem but their skin tans more easily and frequently. Many cases skin colour become dark as result of post inflammatory pigmentation after injury (brown marks).
Basically many persons have dark skin from the time of their birth, but there are many others people who have dark skin because of hyper pigmentation and many more reasons. Dark skin has large amount of skin pigment melanin, as contrast to a fair skin. If the quantity of melanin increases than it also makes the skin look discoloured (dark in colour) and patchy. The most commonly seen sign of dark skin is that the skin colour changes into brownish to blackish. The effect increases if it is also come with marks or dark patches on the skin. Using proper medication can easily cure dark skins.