Not to be confused with the Oreotrochilus genus, the White-tailed Hillstar is the only member of the Urochroa genus. It is rather large and streamlined, showing lots of different colors around the body. Its throat is blue to purple, ending on a dark orange malar strip which is very conspicuous. The belly is gray but shows blue-green feathers on the sides. The back and head of the body has olive, blue and green hues. A very small white postocular spot finishes the look.