Topics Animals, plants and life

How do chameleons change color?

Chameleons change color mainly by changing how light bounces off their skin. In the species studied most closely, the skin holds layers of cells packed with tiny crystals. When the animal relaxes or tightens those cells, the spacing between the crystals shifts, and so does the color of light they reflect. Pigments, including dark melanin in deeper layers, add to the effect.

What makes it interesting is how much the popular story gets wrong. Many people think chameleons simply match whatever they sit on. Camouflage plays a part for some species, but color change also seems tied to mood, temperature and signaling to other chameleons, and scientists still debate how much each matters. Not every species has been studied equally, so some details are open.

An episode would walk through the skin layer by layer, then ask why the animal evolved this ability at all. This page comes from bre, an app whose hosts are AI, so they can be wrong. You can press Talk during an episode and ask your own question, such as how fast the change happens.

What a bre episode would cover

An outline of the episode bre would make for this question. Every episode is written fresh when you ask, so yours will differ.

  1. The myth of the background matchMany people think chameleons copy their surroundings like a living photograph. The picture is more complicated, and the episode starts by separating the myth from what is observed.
  2. A skin built in layersChameleon skin holds several cell layers, some with pigment and some with reflective crystals. Each layer does a different job in the final color.
  3. Crystals that change spacingIn studied species, nanocrystals in skin cells sit in a lattice. When the lattice loosens or tightens, the reflected color shifts, which is structural color rather than paint.
  4. What the pigments addDeeper layers contain pigments, including dark melanin, that can change how bright or dark the skin looks. Together with the crystals, they shape the full range.
  5. Calm animals and social encountersA 2015 study on male panther chameleons found that color shifts during social interactions involve changes in the spacing of guanine nanocrystals in skin cells. This is shown in that species, and the episode says so.
  6. Why evolve it at all?Signaling, temperature control and camouflage are all proposed reasons. Scientists do not agree on how much weight each deserves, and the episode says so.

How the episode might open

A sample exchange between two of bre’s AI hosts, bre and Arlo. Both are AI; this is written by AI, as every bre episode is.

  1. breAI host

    Everyone says chameleons change color to hide. I believed that for years. Arlo, is that actually the main reason?

  2. ArloAI host

    Debated. Nobody agrees on the weight.

  3. breAI host

    Okay, so if it's not just hiding, what's the rest? Because the color shift itself is wild. What is the skin doing?

  4. ArloAI host

    Crystals. Tiny ones, in the skin. They change spacing, and that changes the color they reflect.

  5. breAI host

    So it's less like paint and more like a soap bubble. The color comes from structure, not from a dye.

  6. ArloAI host

    Big claim. Who counted that?

  7. breAI host

    A 2015 study in Nature Communications, by Teyssier and colleagues, on panther chameleons. It's shown in that species, and I don't know every detail of their methods, but that's the source.

  8. ArloAI host

    Fair. Source named. Crystals, in that species.

Questions people also ask

Do chameleons change color to match their background?
Sometimes, but that is not the whole story. Color change also seems linked to mood, temperature and signaling to other chameleons. Scientists still debate how much camouflage matters compared with those other reasons, and it likely varies by species.
How fast can a chameleon change color?
The change can be fairly quick, in some cases within seconds, though it depends on the species and situation. In studied species, the quick shifts appear to come from changes in skin crystals.
Are chameleon colors from pigment or from structure?
Both play a part. In studied species, structural color from crystals drives the quick shifts, while pigments such as melanin affect brightness and darkness. How the two combine can differ between species, and not all species have been studied closely.
Can all chameleon species change color?
Chameleons are widely known for color change, but the range and the mechanism vary by species. Some shift dramatically, while others change only a little. Research has focused on a few species, so scientists cannot yet say the same mechanism works identically in all.

Related topics

More: all 300 topics, animals, plants and life, or the longer reads on /learn.

bre’s hosts are AI, and every episode is generated, so they can be wrong: check anything that matters. This page outlines what an episode would cover. It is for interest and learning, not medical, financial or legal advice.