Tyrian purple in antiquity because the colour did not easily fade, but instead became brighter with weathering and sunlight. Its significance is such that the name Phoenicia means 'land of purple.' It came in various shades, the most prized being that of "blackish clotted blood". Tyrian purple was expensive: the 4th-century-BC historian Theopompus reported, "Purple for dyes fetched its weight in silver at Colophon" in Asia Minor. The expense meant that purple-dyed textiles became status symbols, whose use was restricted by sumptuary laws. The most senior Roman magistrates wore a "toga praetexta", a white toga edged with a stripe of Tyrian purple.
George Palmer (colour theorist) the complementary nature of the successive contrast effect by stating that it is due to fatiguing of one or two of the light sensor types, an explanation that continues to be accepted as valid, as does his conjecture that the different kinds of sensors take different time intervals to recover upon exposure to strong light. George Palmer (colour theorist) George Palmer (ca. 1746 – March 3, 1826), also known as George Giros de Gentilly, named Palmer) was an English dye chemist, colour theorist, inventor, and soldier. He is best known for his conjectures about colour vision and colour blindness. According