Siphateles bicolor can be distinguished by the following characters: lateral line with 41-64 scales; dorsal fin usually with 8 rays; anal fin with 7-8 rays; pharyngeal teeth 0,5-5,0; deep, compressed body; dorsal-fin origin over pelvic- fin origin; fairly deep caudal peduncle; small, rounded fins; small, terminal to slightly subterminal mouth; does not extend to eye; dusky olive to dark green above; brassy brown side, often mottled in adult; silver white to yellow below; clear to dusky olive fins; young with dusky stripe along side; large individuals may have yellow to copper fins with pink, red, or orange bases, red-orange lower side (Ref. 86798).