text: can a black light be produced? if not, why?   i don't think so.  first, one must look at how we see different kinds of colours.  for example, we see a blue-coloured object because the object reflects blue light into our eyes.  a black-coloured object absorbed all lights falling on it and does not reflect any light.  as no light comes into our eyes from the object, it is seen to be black in colour. on this reasoning, you can't produce a black light.