purpureal

From Latin purpureus (“purple, violet; brown, reddish; clothed in purple; (figurative) brilliant, shining; beautiful”) + English -al (suffix meaning ‘of or pertaining to’ forming adjectives). Purpureus is either derived: * from purpura (“the colour purple; purple-fish (Hexaplex trunculus)”) (from Ancient Greek πορφῠ́ρᾱ (porphŭ́rā, “purple-fish; purple dye obtained from it; purple-dyed cloth; purple stripe or other adornment of a garment”), from πορφύρω (porphúrō, “to redden”)) + -eus (suffix forming adjectives from nouns); or * from Ancient Greek πορφύρεος (porphúreos, “of a purple colour”), from πορφῠ́ρᾱ (porphŭ́rā) (see above) + -εος (-eos).

来源：wiktionary