Centrolene ballux

Adult males measure 19–22 mm (0.75–0.87 in) and females 21–23 mm (0.83–0.91 in) in snout–vent length. The snout is rounded. Both fingers and toes are webbed.^[3][4][6] The tympanum is visible. The dorsum is dark lime green and has minute pale gold-white flecks, which are most numerous on the hind limbs. The tips of digits are yellowish green. The venter is translucent.^[3][4]

Its natural habitats are humid upper montane forests at elevations of 1,700–2,340 m (5,580–7,680 ft) above sea level.^[1][2][4] It occurs in vegetation some 50 to 200 cm above the ground, typically near streams or ditches.^[3][4] Breeding takes place in streams.^[1] It is an endangered species due to climate change (which changes humidity) and habitat loss, possibly also introduced predatory fish as well as pollution and chytridiomycosis. It occurs in Reserva La Planada (private) in Colombia^[1] and in Reserva Las Gralarias in Ecuador.^[4]