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.
Carbene dye dyed. For example, a dye that can colour cotton would usually not be appropriate for dyeing polyethylene, but by using a carbene, the same dye can be used for both. Carbene dye A carbene dye is a reactive dye based on carbene chemistry. A benzophenone is functionalised with a chromophore or group that can be easily converted to a chromophore at a later stage. The functionalised benzophenone is reacted with hydrazine hydrate and subsequently treatment with mercury oxide. The resulting diazo compound is stable at room temperature. On heating, nitrogen gas is released and the carbene generated. The thus generated