re blue led s in article c yqde cq ecf toronto edu gladman ecf toronto edu gladman aviv writes that s why you don t find blue leds or for that matter some other colour of leds that is not to say that blue leds can t be found i ve seen blue leds sold but they were just your typical visible light led in a blue plastic covering no the blue leds sold down the street are in milky white plastic and fyi putting a filter on a typical visible light led presumably meaning a non blue one won t produce blue light a filter can only block light it can t generate wavelengths that aren t there to start with jamie hanrahan kernel mode systems san diego ca internet jeh cmkrnl com uucp uunet cmkrnl jeh cis
