Why do things become darker when they get wet? (e.g blonde hair)

Question: Why do things become darker when they get wet? (e.g blonde hair)
- Keywords:
  colour,
  water
Asked by Zealousy to Rebecca on 17 Jun 2015.
- Rebecca Dewey answered on 17 Jun 2015:
  
  If something has a layer of water covering it, then the water will reflect a lot of the light before the light is allowed to reach the object. Therefore the object (i.e. the hair) will reflect less light and so appear darker!

Question: Why do things become darker when they get wet? (e.g blonde hair)