On average, sun parakeets weigh around 110 g (4 oz) and are around 30 cm (12 in) long. Adults have a rich yellow crown, nape, mantle, lesser wing-coverts, tips of the greater wing-coverts, chest, and underwing-coverts. The face and belly are orange with red around the ears. The base of the greater wing-coverts, tertials, and base of the primaries are green, while the secondaries, tips of the primaries, and most of the primary coverts are dark blue. The tail is olive-green with a blue tip. From below, all the flight feathers are dark greyish. The bill is black. The legs and the bare eye-ring are grey.