Not familiar with video productions here ...     If you want to create any pure Metal, set Diffuse to 0.00 or black and use "Metallic" in Reflection Channel.   If you want to create anything else than a Metall (or Semi Conductor) it is a Dielectric, like most of Building Materials we deal with in Reality. Set Diffuse to an appropriate Color or Texture, also choose the "Metallic Shader in Reflection Channel, like This :     So