Nominate females have a gray-green head including the forehead, and upperparts that are golden green transitioning to the blue-violet rump; all of these colors are duller than those of the male.

[6] The nominate subspecies of blue-throated starfrontlet is found in Colombia's northern and eastern Andes from the Serranía del Perijá, which straddles the border between northern Colombia and northwestern Venezuela, south and west to the Metropolitan Area of Bogotá.

The species inhabits the interior and edges of cloudforest and elfin forest, shrubby slopes, and sometimes bushy landscapes at the lower margin of páramo.

[6] Details of the blue-throated starfrontlet's movements are unknown, but it likely makes season elevational changes.

[6] The blue-throated starfrontlet feeds on nectar by trap-lining, visiting a circuit of a wide variety of flowering plants.

In addition to feeding on nectar it captures small arthropods by gleaning from foliage and sometimes by hawking.

"[6] The IUCN has assessed the blue-throated starfrontlet as being of Least Concern, though its population size and trend are not known.