Edison's first successful light bulb used carbon, but modern light bulb filaments are made of tungsten. As you cool an object, it will continue to radiate less and less light, but you won't see the difference because the light that is radiated below the temperatures that produce a visible glow are in the infrared range. So, the light is not visible to the naked eye. When you see a cool object, it is because the object is reflecting light, not radiating. So cooling it won't make it darker unless it somehow causes it to reflect less. Normally, the reflectivity of a substance is independent of its temperature.