When Lucette (in VN’s novel Ada, 1969, Van's and Ada's half-sister) visits Van at Kingston (Van's American University) bringing him a letter from Ada, Van notices a long, blue, violet-sealed envelope protruding from the bag and muses that chows, too, have blue tongues:
She unclicked her black-silk handbag, fished out a handkerchief and, leaving the gaping bag on the edge of the sideboard, went to the farthest window and stood there, her fragile shoulders shaking unbearably.