Colour

Colour

Colour, or color in American English, is the characteristic of visual perception described through color categories, with names such as red, blue, yellow, green, orange, or purple. This perception of colour derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Colour categories and physical specifications of colour are associated with objects through the wavelength of the light that is reflected from them.

History of Colour Theory

The study of colour dates back to antiquity, with notable contributions from philosophers and scientists such as Aristotle, Isaac Newton, and Johann Wolfgang von Goethe. Newton's work in the 17th century laid the foundation for the modern understanding of colour, demonstrating that white light is composed of a spectrum of colours.

Physics of Colour

Colour is a property of light as seen by people. The science of colour is sometimes called chromatics, colorimetry, or simply colour science. It includes the perception of colour by the human eye and brain, the origin of colour in materials, colour in art, and the physics of electromagnetic radiation in the visible range (that is, what is commonly referred to simply as light).

Colour Perception

The human eye perceives colour when light enters the eye and is detected by the photoreceptor cells in the retina. There are two types of photoreceptor cells: rods and cones. Rods are responsible for vision at low light levels, while cones are active at higher light levels and are capable of colour vision. There are three types of cone cells, each sensitive to different wavelengths of light, corresponding to red, green, and blue.

Colour in Art

Colour plays a crucial role in art and design. Artists use colour to evoke emotions, create depth, and convey messages. The use of colour in art can be traced back to prehistoric times, with the use of natural pigments in cave paintings. In modern times, colour theory has become an essential part of art education, helping artists understand how to mix colours and use them effectively.

Colour in Technology

In technology, colour is used in various ways, from display screens to printing. Digital displays use the RGB colour model, which combines red, green, and blue light to create a wide spectrum of colours. In printing, the CMYK colour model is used, which combines cyan, magenta, yellow, and black inks to produce a range of colours.

Also see

• Visible spectrum
• Color theory
• Color blindness
• Color wheel
• Primary color
• Secondary color