Electric blue is one of my favorite blues. The hue is named for the color of an electrical discharge through the atmosphere (which is to say the fluorescent ion glow of nitrogen). The name is older than you might imagine: according to “A Dictionary of Color,” the first use of the name was in 1845. The blue note of electrical sparks is readily apparent in photos of sparks and discharges—but somewhat less so in the real world where electrical discharges are bright, swift, and unpredictable. A lot of Victorians must have stared at wacky apparatuses for this to become codified as a standard blue.
Nineteenth century scientists realized that there was some connection between electricity and the human nervous system, but they could not quite put it all together. Electric blue therefore became a favorite color for indicating supernatural phenomena. The color became immensely popular in the latter half of the nineteenth century and was used in all sorts of garments, sales brochures, and products. It was a fad color which lasted a long time (since fads spread more slowly in those days).
The color has faded from popularity somewhat, but in our era of glowing screens, glowing blue is never entirely irrelevant (plus, as noted, it has a basis in the physics of electricity and the composition of the atmosphere).