μέλανσις
From LSJ
τὸ κακὸν δοκεῖν ποτ' ἐσθλὸν τῷδ' ἔμμεν' ὅτῳ φρένας θεὸς ἄγει πρὸς ἄταν → evil appears as good to him whose mind the god is leading to destruction (Sophocles, Antigone 622f.)
English (LSJ)
εως, ἡ,
A a becoming black, opp. λεύκανσις Arist.Ph.227b8, 230a23. 2 dyeing black, τριχῶν Alex. Trall.1.3.