This is why the color purple was reserved for triumphant Roman generals

Violet, better known as Tyrian violet, is a unique dye taken from the mollusk murex, originally made by the Phoenician city of Tyre. The difficulty of making the dye, ranging from purple to red, and its maximum resistance to fading made articles dyed Tyrian violet extremely desirable and expensive. Extracting this dye, also known as Imperial Violet, Phoenician Violet, or Royal Violet, involved a mammoth of snails coupled with considerable labor.
Phoenician pioneers
The Phoenicians achieved considerable fame as sellers of Tyrian purple and exported its manufacture to its colonies, particularly Carthage. From there, its popularity spread considerably and was consequently adopted by the Romans, who used it to signify status and imperial authority.
According to Phoenician mythology, the discovery of the Tyrian purple was attributed to Tyros, whose pet dog was stained purple after biting a beached mollusc. Tyros requested a garment of the same color and then started the famous dye industry.
At a glance, each Murex Brandaris snail contains a single drop of the precious liquid. As such, it took at least two hundred and fifty thousand seashells to generate one fluid ounce of purple dye. The need to collect thousands of these creatures made the color purple incredibly invaluable in ancient Rome.
Thousands of Romans harvested sea snails from the large-scale manufacture of Tyrian purple, which were immediately boiled in huge lead vats for several days. Despite the foul smell produced, the artisans harvested the chemical precursors from the snails through light and heat and transformed them into unique and valuable dyes.
Ancient Roman obsession with status
The main purpose of Tyrian purple was to dye textiles, especially the finest quality cloth called Dibapha, which had to be dipped twice in the purple dye. Due to the lengthy production procedure, the large number of shells required, and the striking color range of the finished articles, these dyed textiles were a great piece of luxury.

Therefore, Tyrian purple became a giant status symbol signifying wealth, power and prestige. Roman emperors forbade their citizens to wear purple clothes, and if they did, they would face the death penalty. Purple was a distinct way of showing wealth and distinguishing the upper class in a more layered way than gold. Clothing made from the purple dye was exorbitantly expensive, so a single pound of purple wool was more expensive than a pound of gold, and a pound of purple dye was worth three pounds of gold .
At the same time, the uniqueness and value of the violet dye was attributed to its property which, instead of fading over time, increased brightness with each wash circle. The Romans adopted imperial purple since higher-ranking magistrates were dressed in the toga praetexta, a white toga with a distinct purple stripe. When Roman generals celebrated a Roman triumph, the highest honor a general could achieve, they were allowed to don the unique purple Toga Picta.
Subsequently, purple became associated with the emperor and his assistants. Over the next few centuries, the Roman government made extraordinary efforts to nationalize violet color production and set aside the unique dye for the emperor. In the Eastern Roman Empire, purple was reserved for the emperor. Moreover, it was also used for the most crucial imperial documents. Overall, a drop of purple on an individual’s clothing was a unique mark to distinguish him as an imperial administrator or bishop.