>What I want to know is why is there a purple street light on every block? The simple answer is: they installed cheap, shitty LED street lamps. The expanded answer: White LED street lamps are actually blue/violet LEDs that excite a yellow phosphor to make "White" light. Yellow and blue are opposite each other on the color wheel. Red and green light combined produce yellow, hence yellow is composed principally pf red and green light. White light can be approximated by combining red, green and blue light. So, if yellow light is composed of red and green light, adding blue makes an approximate White light. It's close but not perfect. That yellow phosphor coating is not integrated into the LED. It is simply "painted" on to cover the blue/violet LED chip(s). If the LEDs are cheap, shitty or otherwise not made to quality specification with good materials, the heat from the high intensity LEDs, the weather and outdoor exposure causes the phosphor to fall off thereby exposing the blue/violet LED. This is why they turn purple. They are literally falling apart when they turn that way. They are shit quality street lamps.