And when they just started being available, props designers for scifi loved them because LEDs work much better on screen than incandescent bulbs, and blue lights were something people didn’t have yet in their household objects so a blue LED was 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 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 to the scifi trend, made stuff looked like scifi future tech you could have in real life.

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