And when blue LEDs just started being available prop designers for scifi loved them because LEDs work much better on screen than incandescent bulbs, and as blue lights were something people didn’t have yet in their household objects they looked new and interesting. Look at the Doctor Who and Torchwood props from the mid 2000s, everything from the iconic Sonic Screwdriver to alien zappers and bleepers and greebles of all kinds were full of tiny blue lights because it screamed “scifi” to the viewer.

Very quickly, though, blue LEDs got cheap enough for everyday junk and manufacturers immediately shoved them into every consumer product because they were new and interesting and, thanks in part to the scifi trend, made stuff look like scifi future tech you could have in real life.

Now, a couple decades on, we’re still kind of stuck there.