Phaedyma columella has upper wings which are dark brown to black with white patches. On the forewings there is a narrow and short white cell line, the spots in space 1a are elongated. On the hind wing there is a broad disc band, the speculum above the side of the hind wing protrudes. The underside of the wings are yellowish brown with the same marking as the upper side. In males, the 8 veins of the hind wings terminate in a termen just below the wing apex.
Larva: The larvae of Phaedyma columella are brown in color, the body is shaped like a saddle from the 3rd thoracic segment to the 8th ventral segment, the saddle is light yellowish brown in color. The surface of the body is covered by a small turbecles, in addition there are longer, tapered and branched spines on the 2nd and 3rd thoracic segments as well as on the 2nd and 8th abdominal segments. The head capsule is light brown in color with dark lateral and medium stripes.
Pupa: The pupa of Phaedyma columella is pale brown in color with a pair of oval silver patches on the dorsum of the metathorax, the belly is slender and the thorax is large and the wing box extends to the sides. The dorsum of the thorax is angled, the head is split at its front edge with a small, tapered lateral knot.