By Mark Kotterink, director of the Dutch Colour Institute (SNKI) · Published 12 March 2026 · Updated 8 October 2026
The Natural Colour System (Theory)
NCS is a perceptual colour model: it organises colours as we see them, using six elementary colours, a nuance (blackness, whiteness, chromaticness) and a hue.
The Natural Colour System (NCS) is a perceptual colour model that organises colours based on human perception. The starting point is not how colours are made, but how colours are seen.
The system describes every colour using psycho-visual characteristics that are recognisable to everyone, regardless of language, discipline or technical knowledge.
The Six Elementary Colour Associations
Research into colour perception has shown that people spontaneously relate colours to six fundamental colour associations:
All other colours are perceived by the brain as combinations or resemblances of these six.
These six form the psychological foundation of the NCS system.
Three Perceptual Dimensions of Colour
Every colour we see can be described using three visual characteristics:
These three dimensions together form the visual nuance of a colour.
Hue and the NCS Colour Circle
In addition to the nuance dimensions, NCS uses a hue component to indicate how a colour relates to the elementary colour associations.
A colour may, for example, show resemblance to:
- Yellow
- Yellow → Red
- Red → Blue
- Blue → Green
- Green → Yellow
These positions form the NCS colour circle.
It is a perceptual, not a physical circle.
The Nuance Structure (Triangle Model)
In addition to the colour circle, the NCS structure includes a nuance triangle, in which every colour is assigned a ratio of:
- blackness
- whiteness
- chromaticness
This allows every colour to be placed purely visually within the three-dimensional NCS model.
Why NCS Is Scientifically Consistent
NCS is theoretically stable because:
- it is based on human vision, not on technical models
- the structure aligns with how our brain forms colour categories
- colour relationships are logical and reproducible
- all colours can be described without material or pigment
- the system is independent of paint technique, digital colour models or light source
This makes NCS applicable in any design, production or technical context.
Applicability of the Colour Model
The strength of the theory is that it:
- is independent of technology
- works consistently across materials
- intuitively aligns with how people understand colour
- provides an exact starting point for all further NCS applications
This allows the model to function as the backbone of professional colour communication.
Frequently asked questions
What is a perceptual colour model?
A colour model that organises colours according to how people see them, not according to how they are technically produced with pigment, ink or light. NCS is such a model: it describes every colour using psycho-visual characteristics that are recognisable to everyone, regardless of language, discipline or technical knowledge.
Which six elementary colours does NCS use?
White (W), black (S), yellow (Y), red (R), blue (B) and green (G). Research into colour perception has shown that people spontaneously relate colours to these six associations. All other colours are perceived as combinations or resemblances of them; they form the psychological foundation of the system.
What is the difference between nuance and hue?
The nuance describes how strong a colour is: the ratio between blackness, whiteness and chromaticness. The hue describes which direction the colour has on the colour circle, for example between yellow and red. Together they place a colour in the three-dimensional NCS model.
Is chromaticness the same as saturation?
No. Chromaticness in NCS is the perceived colourfulness: how powerful or present the colour is to the eye. Saturation in the technical sense is a property of a light or ink mixture. NCS deliberately uses the perceptual intensity, so that the concept is independent of material or technique.
Why is the NCS colour circle not a physical circle?
Because it is not based on pigments or light wavelengths, but on how people subjectively organise colours in a logical pattern. The four chromatic elementary colours are therefore placed at equal distances, even though their wavelengths are not. That makes the circle usable for every material and every light source.
Why is NCS scientifically consistent?
The model is based on human vision and aligns with how the brain forms colour categories. Colour relationships are therefore logical and reproducible, and every colour can be described without reference to material, pigment, paint technique, digital colour model or light source. That is why it is applicable in any design, production or technical context.
Take the online NCS colour course at the Kleurenschool ↗
Mark Kotterink, director of SNKI. Colour expert, lecturer and researcher with 35 years of experience in colour technology and colour application.