The Martin–Schultz scale is a standard color scale commonly used in physical anthropology to establish more or less precisely the eye color of an individual; it was created by the anthropologists Rudolf Martin and Bruno K Schultz in the first half of the 20th century. The scale consists of 20 colors (from light blue to dark brown-black) that correspond to the different eye colors observed in nature due to the amount of melanin in the iris (in this case, the lower the number, the lighter the eye color):Piquet-Thepot M.-M. - Bulletins et Mémoires de la Société d'anthropologie de Paris, XII° Série, tome 3 fascicule 3, pg. 207,208 - (1968) ColorNameMartin–Schultz scalepale-blue iris1alight-blue iris1bsky-blue iris1cblue iris2adark-blue iris2bblue-gray iris3light-gray iris4adark-gray iris4bblue-gray iris with yellow/brown spots5gray-green iris with yellow/brown spots6green iris7green iris with yellow/brown spots8amber iris9hazel iris10light-brown iris11medium-brown iris12dark-brown iris13mahogany iris14black-brown iris15black iris16 See also Eye color Martin scale Human eye References