ungreen

1. (dyeing) To expose to air after dyeing in indigo so that the greenish color fades away.Examples: "When necessary to air and ungreen, by drawing the pulley the frame rises, and the cloth drains into the vat."; "After the expiration of this time, suspend a second lock of wool for ten or fifteen minutes in the Vat; when it comes out, it should be of a deeper shade, and more like a grass green than the first lock was: it will take a little over five minutes to ungreen it, when it will assume almost a Middle Blue, with a slight tinge of Green, after it has been exposed to the air for half an hour."; "After each immersion the champignon is lifted out of the vat, and the fabrics are left to ungreen themselves by contact with the air. (It must be observed that, although soluble indigo is called white, because it is without color when carefully prepared in the laboratory, the goods, when first taken from the ordinary vat, are of a green color.)"