cf. generally alpha 1624, alpha 1625, alpha 1626, alpha 1627. The present entry comes from the scholia to Aristophanes, Lysistrata 150, where the phrase ka)n toi=s xitwni/oisi toi=s *)amorgi/nois occurs (web address 1). The scholia read in full: "some say the appearance of the color is as olive lees; some say the Amorgian chitons from the island of Amorgos, as 'Therian' from the island of Thera." The lexica give equal support to both a color and to a style of garment or fabric, particularly of a diaphanous sort; cf. alpha 1626 and LSJ s.v. (web address 2). Forbes (below) denies that the garments could have been made from flax grown on Amorgos, as the island is too rocky to grow flax. In fact, he does not regard it as having been flax but silk of some sort.
[1] "Therian" seems to refer to garments, not a color.