They have a reflective silver metallic appearance which is achieved through thin film interference within layers of chitin. These layers of the chitin coating are chirped (in layers of differing thicknesses), forming a complex multilayer as each layer decreases in depth; as the thickness changes, so too does the optical path-length. Each chirped layer is tuned to a different wavelength of light. The multilayer found on C. limbata reflects close to 97% of light across the visible wavelength range.

Nature is insane