Spectacular male shows diagnostic maroon sides to head and collar, iridescent metallic blue-green forehead and crown, blue shoulder, moss-green back, and yellow rump. Underside is uniform bright yellow in both sexes, although female is entirely olive above. Juvenile resembles female but with pale legs. Singles and pairs inhabit forest, shrubbery, and plantations in lowlands and lower hills, often joining mixed-species flocks. Female can be separated from female Black and Brown-throated Sunbirds by bright yellow underparts and lack of yellow eyebrow. Gives high-pitched “tzeeet” calls. Song is an undulating trill.