In the traditional color wheel used by painters, violet and purple are both placed between red and blue. Purple occupies the space closer to red, between crimson and violet. Violet is closer to blue, and usually less intense and bright than purple.

From the point of view of optics, violet is a real color- it occupies its own place at the end of spectrum of light, and was one of the five primary colors of the spectrum first described by Isaac Newton in 1672, whereas purple is simply a combination of two colors, blue and red.

In the Roman Republic, the togas of all citizens were bordered with a purple stripe. During a triumph, the general being honored wore an entirely purple toga bordered in gold. The commander of the army wore a purple cloak, called a paludamentum. During the Roman Empire, purple was reserved for the Emperors. The Emperor Caligula had a the King of Mauritania assassinated for wearing a purple mantle better than his own. Nero made it punishable by death for anyone else to wear the color.