Chameleon-like 'opal' can take on any colour - tech - 23 December 2008 - New Scientist

[dracodraconis]

Chameleon-like 'opal' can take on any colour - tech - 23 December 2008 - New Scientist

A new synthetic material has been developed that can adopt any colour in the visible spectrum. The material starts blue, but applying voltage causes the colour of the material to gradually become red, passing through the entire spectrum in the process. They hope to use the material to develop a full-colour electronic paper that requires little energy. Apply voltage changes the colour, but as soon as the voltage is removed it stays that colour. Given that the process is ultimately the oxidation of iron, it's not clear whether the process is reversible so you may want to take dreams of full colour electronic paper with a grain of salt.