Why blue in particular? Well, blue was the last -- and most difficult -- advance required to create white LED light. And with white LED light, companies are able to create smartphone and computer screens, as well as light bulbs that last longer and use less electricity than any bulb invented before.
LEDs are basically semiconductors that have been built so they emit light when they're activated. Different chemicals give different LEDs their colors. Engineers made the first LEDs in the 1950s and 60s. Early iterations included laser-emitting devices that worked only when bathed in liquid nitrogen. At the time, scientists developed LEDs that emitted everything from infrared light to green light… but they couldn't quite get to blue. That required chemicals, including carefully-created crystals, that they weren't yet able to make in the lab.
Once they did figure it out, however, the results were remarkable. A modern white LED lightblub converts more than 50 percent of the electricity it uses into light.