By Mark Kotterink, director of the Dutch Colour Institute (SNKI) · Published 12 March 2026 · Updated 8 October 2026
An NCS colour code such as S 2050-Y90R describes what a colour looks like: 20% blackness, 50% chromaticness and a hue from yellow towards red. The code is independent of material.
Introduction
The Natural Colour System (NCS) is an internationally recognised system that describes colours as the human eye perceives them. NCS makes it possible to unambiguously designate any conceivable colour, regardless of material, medium or production process.
An NCS colour code is the precise notation by which a colour is recorded within this system — essential for designers, architects and colour professionals.
What does an NCS colour code look like?
A standard NCS colour code may look like this, for example:
This code contains all relevant information about how the colour is visually perceived: blackness, chromaticness and hue.
For example: S 2050-Y90R describes a colour that belongs to the standard NCS colours, with 20% blackness, 50% chromaticness and a hue in the yellow-red quadrant that shifts 90% towards red. The colour therefore appears virtually red, but formally still belongs to the yellow hue family.
The six elementary colours of NCS
In the NCS system, all colours are analysed in terms of resemblance to six "elementary colours", as our eye perceives them:
All other colours are visual mixtures, expressed as resemblance to two or more of these elementary colours.
Why does NCS work as a colour code system?
- 1Visual & perception-basedNCS describes colours as we see them, not how they are technically mixed. This makes the notation intuitive and relevant for design, communication and visualisation.
- 2Universally applicableThe same NCS code applies regardless of whether the colour is used on paint, textiles, plastics, digital displays or print.
- 3Standardised and objectiveBecause the system is recognised and used worldwide, colours can be precisely specified, communicated and identified in design, production and quality control.
Practical use of an NCS colour code
With an NCS colour code you can:
- Communicate colours precisely with clients, suppliers or manufacturers.
- Compare colour samples and fans and specify paint products exactly.
- Design colour harmonies and colour schemes with reliable references.
- Apply colours consistently — regardless of material or production method.
Frequently asked questions
What is an NCS colour code?
An NCS colour code is the notation that defines a colour unambiguously within the Natural Colour System, for example S 2050-Y90R. The code describes how the colour looks: how much blackness, how much chromaticness and which hue. That is why the same code works on paint, textile, plastic, print and screen.
How do I read S 2050-Y90R?
S stands for standard colour: NCS issues this colour as a standard sample. The first two digits (20) give the blackness, the second two (50) the chromaticness. Y90R is the hue: yellow shifted 90% towards red. The whiteness is not in the code but follows from 100 − 20 − 50 = 30.
What does the letter S at the start of an NCS code mean?
The S stands for standard colour: NCS issues the colour as a controlled standard sample. A code without S, such as 1487-Y65R, is a valid NCS notation, but not an NCS standard colour, unless NCS issues that colour as an S colour. The structure of the digits and the hue is otherwise the same.
What is the difference between an NCS code and a RAL number?
A RAL number is a sequence number in a collection and says nothing about what the colour looks like. An NCS code is descriptive: from the code itself you can read whether the colour is light or dark, muted or vivid, warm or cool. That lets you compare and order colours with NCS without having seen them.
What does N mean in an NCS code such as S 1500-N?
N stands for neutral: the colour has no hue and is a grey between white and black. S 0300-N is almost white, S 9000-N almost black. For neutral colours the chromaticness is always 00.
Can I judge an NCS code on my screen?
No, only as an indication. Screens show colour differently and most are not calibrated. For choosing or checking a colour, use a physical NCS colour fan deck or colour sample, preferably in the light where the colour will finally be applied.
Mark Kotterink, director of SNKI. Colour expert, lecturer and researcher with 35 years of experience in colour technology and colour application.