Abstract: An electrical fuse features a pyrotechnic smoke-generating mixture supported proximate to or adheringly supported on a meltable fuse wire element. A portion of the fuse housing is transparent. Upon either low current or high current blowout the local temperatures attendant thereto cause ignition of the pyrotechnic mixture and evolution of a cloud of colored smoke which deposits on the interior of the transparent portion of the housing to yield a readily visible indication that the fuse has blown. Additionally, when the fuse is operated at temperatures close to blowout conditions, a different colored smoke is produced to indicate incipient fuse deterioration.