originally denoted the "purple-fish," then, "purple dye" (extracted from certain shell fish): hence, "a purple garment," Mark 15:17,20; Luke 16:19; Revelation 18:12 .
"purple, a reddish purple," is used of the robe put in mockery on Christ, John 19:2,5; in Revelation 17:4 (in the best texts; some have No. 1); 18:16, as a noun (with himation, "a garment," understood).