Acolourant/colour additive (British spelling) orcolorant/color additive (American spelling) is a substance that is added or applied in order to change thecolour of a material or surface. Colourants can be used for many purposes includingprinting,painting, and for colouring many types of materials such asfoods andplastics. Colourants work by absorbing varying amounts oflight at differentwavelengths (orfrequencies) of itsspectrum, transmitting (if translucent) or reflecting the remaining light in straight lines orscattered.
Most colourants can be classified asdyes orpigments, 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 asbinders andfillers are added, for example inpaints andinks. In addition, some colourants impart colour through reactions with other substances.
Colourants, or their constituentcompounds, may be classified chemically asinorganic (often from a mineral source) andorganic (often from abiological source).
In the US, theFood and Drug Administration (FDA) regulates colourants for food safety and accurate labelling.[1]
Authority control databases: National |
|---|
 | This colour-related article is astub. You can help Wikipedia byexpanding it. |