<P> Studies on Caucasian twins, both fraternal and identical, have shown that eye color over time can be subject to change, and major demelanization of the iris may also be genetically determined . Most eye - color changes have been observed or reported in the Caucasian population with hazel and amber eyes . </P> <P> Carleton Coon created a chart by the original Martin scale . The numbering is reversed on the scale below in the (later) Martin--Schultz scale, which is (still) used in physical anthropology . Light and light - mixed eyes (16--12 in Martin scale) </P> <P> Pure light (16--15 in Martin scale) </P> <Ul> <Li> 16: pure light blue </Li> <Li> 15: gray </Li> </Ul>

Where does dark hair and green eyes originate