Late Middle English: via medieval Latin from Greek porphuritēs, from porphura 'purple'.

• purple from Old English:

  Just as crimson is named after an insect, so purple is named after a shellfish, and at one time these two words described the same colour. The first thing to be described as purple was a crimson dye obtained from some molluscs, called porphyra in Greek, the source also of the name of the purple stone called porphyry (Late Middle English). The dye was rare and expensive and was used for colouring the robes of Roman emperors and magistrates. The actual colour of the dye varied widely, and over time the word came to mean the colour between red and blue that we now call purple. From the late 16th century purple has been used to mean ‘striking’ or ‘ornate’ in phrases such as purple prose or a purple patch. The latter term, describing an over-elaborate passage in a literary composition, is a translation of Latin purpureus pannus and comes from the Roman poet Horace's Ars Poetica: ‘Works of serious purpose and grand promise often have a purple patch or two stitched on, to shine far and wide’.