Dark, with basal upper ridge of culmen sharply keeled, gape wide, and tail graduated. Male nominate race has velvety black plumage with purple and/or magenta sheens; fine scale-like lores; head iridescent metallic green-blue, washed purplish; tertials iridescent green-blue to blue, washed purple to magenta; iris dark brown; bill shiny black, conspicuous bare gape-flanges and mouth interior yellowish-white sometimes with pale pink or green hue; legs dark olive-brown to blackish. Female differs radically from male in having olive-green plumage, notably browner on wings and tail, more yellowish on belly, and no gape-flanges; also on average fractionally smaller. Juvenile is grey, this plumage worn only briefly; immature male similar in plumage to adult female, has more pointed, longer rectrices than adult male, acquires shorter tail progressively with age; subadult male varies from being like adult female but with few feathers of adult male plumage intruding, to being like adult male with few feathers of female-like plumage remaining, Race amethysdinus differs from nominate in that male has violet-purple iridescent upper tertiais, female slightly longer tail; inexpectatus male has much more green iridescence on tertials. female has slightly shorter tail.