Colourchange

Colourchange refers to the phenomenon where the perceived colour of an object or substance alters. This alteration can occur due to a variety of factors, including chemical reactions, physical changes, or optical effects. In chemistry, thermochromism is a well-known example, where a substance changes colour in response to temperature variations. Liquid crystals and certain dyes exhibit this property, finding applications in mood rings, thermometers, and novelty items. Photochromism describes colour changes induced by light, such as the darkening of transition lenses in eyeglasses when exposed to sunlight. This is a reversible process, with the lenses returning to their clear state in the absence of UV radiation.

Another form of colour change is electrochromism, where the colour can be altered by applying an electrical voltage. This is utilized in smart windows that can adjust their tint, and in some electronic displays. Metamorphism in minerals can also lead to colour changes as the crystal structure rearranges under heat and pressure, creating new mineral phases with different optical properties. Biological organisms also display colour change for camouflage, communication, or thermoregulation. Chameleons are famous for their ability to shift skin colour, while some cephalopods can rapidly alter their appearance. Understanding the mechanisms behind colour change is crucial for developing new materials and technologies across diverse scientific and industrial fields.