An illuminable transmission cable includes an electrical conductor, a light-diffusing fiber having a glass core and a cladding, at least one of the glass core and a core-cladding interface having a plurality of scattering structures. The light-diffusing fiber is configured to optically couple with a light source which emits light into the light-diffusing fiber. The scattering structures are configured to scatter the emitted light and output the emitted light along at least a portion of a sidewall of the light-diffusing fiber. A light transmissive jacket surrounds the electrical conductor and the light-diffusing fiber.