why do chameleons change colors

Question: why do chameleons change colors
- Keywords:
  chameleons,
  color
Asked by Anna to Avani, Jeff, Kenzi, Lindsay, Zoe on 14 May 2015.
- Zoe GetmanPickering answered on 14 May 2015:
  
  Chameleons use color changing for communication. Females and juveniles are very dull, while the adult males have bright colors. If a male chameleon sees a sexy lady chameleon he might change his colors to try to impress her. If he sees a rival male he might show off his colors to try to intimidate the competition. The more you know about animal mating, the more similar human males and other animal males seem: always doing silly things to impress the ladies.
  New scientific discoveries have shown that the chameleon’s cells change colors because of nanocrystals (really really tiny crystals). The chameleons can change the conformation of their cells. As the nanocrystals move around, it changes how they reflect light, thus changing the color that you see.
  
  @Anna-I saw that your least favorite thing about science is the tests. Don’t worry. Scientists don’t take tests once they get their PhD.
- K. Lindsay Hunter answered on 19 May 2015:
  
  I confess I had an idea, but didn’t know this one off the top of my head! YAY, GOOGLE! 🙂
  
  Like Zoe has already explained, a lot of chameleon color changes are a way of communicating, but it also can share information about their emotional state! When chameleons are calm and just hanging out, the nanocrystals in their cells that Zoe just mentioned are really close together, and so they reflect shorter wavelengths like the color blue. When they’re excited, like, when a good-looking lady chameleon has crossed their path, the nanocrystals start to space out and reflect longer wavelengths like yellow, red, and orange. Pretty cool, huh?
  
  You can learn more here:
  http://www.livescience.com/50096-chameleons-color-change.html
- Jeff Shi answered on 20 May 2015:
  
  Yet ANOTHER reason chameleons might change color is to help with temperature regulation throughout the day. As you’ve probably noticed, you get much hotter when wearing dark colors in the sun than light colors!