Light skin of UVA can penetrate deeply into the dermis in persons with light skin pigmentation with little protective melanin pigment. The characteristic of fair skin, red hair, and freckling is associated with high amount of pheomelanin, little amounts of eumelanin. This phenotype is caused by a loss-of-function mutation in the melanocortin 1 receptor (MC1R) gene. However, variations in the MC1R gene sequence only have considerable influence on pigmentation in populations where red hair and extremely fair skin is prevalent. The gene variation’s primary effect is to promote eumelanin synthesis at the expense of pheomelanin synthesis, although this contributes to very little
Pigment Constantinople. The pigment was expensive and complex to produce, and items colored with it became associated with power and wealth. Greek historian Theopompus, writing in the 4th century BCE, reported that "purple for dyes fetched its weight in silver at Colophon [in Asia Minor]." Mineral pigments were also traded over long distances. The only way to achieve a deep rich blue was by using a semi-precious stone, lapis lazuli, to produce a pigment known as ultramarine, and the best sources of lapis were remote. Flemish painter Jan van Eyck, working in the 15th century, did not ordinarily include blue in