Purple  Purple refers to any of a variety of colors with hue between red and blue. Purple is closely associated with violet. In optics, purple and violet refer to colors that look similar, but purples are mixtures of red light and blue or violet light, whereas violets are spectral colors (of single wavelengths of light). In common usage, both refer to colors that are between red and blue in hue, with purples closer to red and violets closer to blue. Similarly, in the traditional painters' color wheel, purple and violet are both placed between red and blue, with purple closer to red. Purple has long been associated with royalty, originally because Tyrian purple dye was extremely expensive in antiquity. Purple was the color worn by Roman magistrates; it became the imperial color worn by the rulers of the Byzantine Empire and the Holy Roman Empire, and later by Roman Catholic bishops. Similarly in Japan, the color is traditionally associated with the emperor and aristocracy. According to contemporary surveys in Europe and the United States, purple is the color most often associated with royalty, magic, mystery, and piety. When combined with pink, it is associated with eroticism, femininity, and seduction. The modern English word "purple" comes from the Old English "purpul," which derives from Latin "purpura", which, in turn, derives from the Greek ("porphura"), the name of the Tyrian purple dye manufactured in classical antiquity from a mucus secreted by the spiny dye-murex snail. The first recorded use of the word "purple" dates to the late 900s AD. Purple is closely associated with violet. In common usage, both refer to colors that are between red and blue in hue, with purples closer to red and violets closer to blue. Similarly, in the traditional painters' color wheel, purple and violet are both placed between red and blue, with purple is closer to red. In optics, violet is a spectral color: It refers to the color of any different single wavelength of light on the short wavelength end of the visible spectrum, between approximately 380 and 450 nanometers, whereas purple is the color of various combinations of red, blue, and violet light, some of which humans perceive as similar to violet. In humans, the L (red) cone in the eye is primarily sensitive to long wavelength light in the yellow-red region of the spectrum, but is also somewhat sensitive to the shorter wavelength violet light that primarily stimulates the S (blue) cone.