The little yellow is just what the name says it is. The upper side is yellow with a black border and forewing tip. The lower side is yellow with a few spots, including two tiny black spots on the basal hindwing. Most individuals have a large round rusty spot on the lower-side hindwing margin, although the spot may be faint or missing in males. Pale yellow females are common, but white, truly albino females are rare. Because they perch with their wings closed, you will only see the black borders on the upper side of the wings when they are flying.
Larvae are green with a white stripe along each side; the bodies are downy.