A colourant/colour additive (British spelling) or colorant/color additive (American spelling) is a substance that is added or applied in order to change the

colour Color (or colour in Commonwealth English; see spelling differences) is the visual perception based on the electromagnetic spectrum. Though color is not an inherent property of matter, color perception is related to an object's light absorp ...

of a material or surface. Colourants can be used for many purposes including

printing Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ...

painting Painting is a Visual arts, visual art, which is characterized by the practice of applying paint, pigment, color or other medium to a solid surface (called "matrix" or "Support (art), support"). The medium is commonly applied to the base with ...

, and for colouring many types of materials such as

foods Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or Mineral (nutrient), minerals. The ...

and

plastics Plastics are a wide range of synthetic or semisynthetic materials composed primarily of polymers. Their defining characteristic, plasticity, allows them to be molded, extruded, or pressed into a diverse range of solid forms. This adaptab ...

. Colourants work by absorbing varying amounts of

light Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...

at different

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

s (or

frequencies Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...

) of its

spectrum A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

, transmitting (if translucent) or reflecting the remaining light in straight lines or scattered. Most colourants can be classified as

dye Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...

s or

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

s, or containing some combination of these. Typical dyes are formulated as solutions, while pigments are made up of solid particles suspended and are generally suspended in a vehicle (e.g., linseed oil). The colour a colourant imparts to a substance is mediated by other ingredients it is mixed with such as

binders Ring binders (loose leaf binders, looseleaf binders, or sometimes called files in Britain) are large folders that contain file folders or hole punched papers (called loose leaves). These binders come in various sizes and can accommodate an arra ...

and

fillers In animal feed, a filler is an ingredient added to provide dietary fiber, bulk or some other non-nutritive purpose. Products like corn fiber (corncobs), fruit fibers (pulp), rice bran, and whole grains are possible fillers. Purpose As source ...

are added, for example in

paint Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are ...

s and

ink Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, or design. Ink is used for drawing or writing with a pen, brush, reed pen, or quill. ...

s. In addition, some colourants impart colour through reactions with other substances. Colourants, or their constituent compounds, may be classified chemically as

inorganic An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''. Inor ...

(often from a mineral source) and organic (often from a

biological Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of ...

source).

Regulation

United States

In the US, the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) regulates colourants for food safety and accurate labelling.

References

Color {{Colour-stub ja:色素 pt:Corante

Regulation

United States

See also

References