1 Basic Colour Attributes


International lighting vocabulary (Commission Internationale de l’Eclairage [CIE]) 

The dimensions of colour -  Glossary (David Briggs)

For additional online glossaries see 12 Further Information.

What is a Colour?

The Commission Internationale de l'Eclairage (CIE) International Lighting Vocabulary recognizes and defines two distinct senses of the word colour: perceived colour and psychophysical colour:

colour (perceived) (CIE) 

colour (psychophysical) (CIE) 

The word "colour" is also used in several other senses colloquially or by individual authors. Paul Green-Armytage (2006) distinguished five such additional "kinds of thing that colours are variously understood to be": conventional colour, substance colour, formula colour, spectral profile colour and inherent colour. For example when artists loosely speak of their paints as "colours" and of mixing paints as "mixing colours" the word "colour" is being used in the sense Green-Armytage identifies as substance colour.

Last but not least, contemporary philosophers hold a diverse range of positions on the fundamental nature of colour (colour ontology); for an introduction to these views see the links below.

Colour subjectivisms: What, why, and which one? (Derek H. Brown)

What is a colour? Scientific opinion about colour and colour measurement (David Briggs)

Color (Stanford Encyclopaedia of Philosophy)

Color (Internet Encyclopaedia of Philosophy)

Color (PhilPapers)

Attributes of Perceived Colour

In the image on the left we perceive a cube having a uniform orange colour belonging to it, as if it were painted all over with an orange paint of the same hue, lightness and chroma (around Munsell 10R 6/14). The object-colour attributes of lightness and chroma are perceived as belonging to an object because they exhibit a tendency towards stability, called colour constancy, under varying viewing conditons, especially varying intensities of the same illumination. In contrast, planes A to C appear successively brighter and more colourful, but this varying brightness and colourfulness is perceived as being imposed by the illumination rather than as belonging to the object itself; they describe the varying appearance of the light reaching our eyes from different areas of the object. Similarly, we perceive the lighter-coloured areas of the floor as being white things of uniform high lightness, yet at the same time the light from these areas varies greatly in brightness. When we can freely examine an object in daylight, the colour we perceive as belonging to it (and might understandably consider to be its seemingly intrinsic colour) is usually a good indication of the overall spectral reflectance of the object at the level of its long-, middle and short-wavelength components, as perceivable to the human visual system. 

The CIE e-ilv currently recognizes and defines six attributes of perceived colour: hue, brightness, lightness, colourfulness, saturation and chroma. A seventh attribute of perceived colour, comprising blackness and its inverse brilliance, is featured in some other systems.

The Elements of Colour (David Briggs)

How Many Dimensions Are Required to Describe Color Appearance? (Mark Fairchild)

hue (CIE) 

unique hue (CIE)

A. Generic opponent hue scale based on even spacing of the four unique hues. B: Munsell hue scale, based perceptually even spacing, showing locations of the hues conventionally regarded as middle red, yellow green and blue in naming artists's paints.. C: Traditional colour wheel of Itten (1961; 1973 edn).. Eliminating green as a primary and spacing middle red, yellow and blue symmetrically makes this scale very uneven perceptually. After Briggs, Where is Colour Education Now? (2018).

lightness (of a related colour) (CIE) 

chroma (CIE) 

brightness (CIE) 

colourfulness (CIE) 

saturation (CIE) 

Illustration of lightness, chroma, brightness, colourfulness and saturation from The Dimensions of Colour (David Briggs)

The perception of color as espoused by Ralph M. Evans of the Eastman Kodak Company and its extension to what is known now and what remains to be seen (R. L. Heckaman and Mark D. Fairchild, Rochester Institute of Technology)

In this image created by R. Beau Lotto, two physically matching image areas evoke a dimly-lit tile exhibiting fluorence on the near face and a strongly lit tile exhibiting moderate blackness on the top face. It is remarkably difficult to see that these two image areas match unless a reference perceived to be outside the scene lighting is included (right) or the rest of the image is masked (see "Illusion 3" here)

 Psychological color order systems (Rolf Kuehni and Andreas Schwarz)

Diagrams showing lines of equal lightness, (top left), chroma (top right), saturation (bottom left) and blackness (bottom right) on a generic object-colour hue page from Color Ordered: A Survey of Color Systems from Antiquity to the Present by Rolf G. Kuehni, Andreas Schwarz (2008). Source: Google Books preview.

The dimensions of colour: The dimensions introduced (David Briggs)

Dimensions of color for artists (David Briggs)

colormaking attributes (Bruce MacEvoy)

Lightness (L), chroma (C) and saturation (S) for a red violet hue from Handprint by Bruce MacEvoy

Hue, Lightness and Chroma

This widely used set of perceived-colour attributes is known both from its quantitative manifestations in the Munsell System, the L*Ch representation of CIE L*a*b*space, and the RAL D4 Colour Atlas, and as the generic qualitative framework used by many artists and designers (for whom the concept of chroma often goes by the name "saturation" - see below). For many additional links specific to the Munsell System see the entry for that system on the Colour Order Systems page.

While one could describe colours in terms of hue, lightness and saturation in their scientific senses, it is usually clear when this combination of terms is encountered that the word "saturation" is intended to mean chroma rather than saturation as defined in standard CIE terminology. An exception is in the  commonly used digital colour space called either HSB or HSV ("hue, saturation and brightness/value" ), where the the "S" is a measure of relative saturation rather than chroma. (In another space called HLS  for "hue, lightness and saturation", the "S" stands for a measure of relative chroma. For the meanings of so-called "lightness", "brightness" and "saturation" parameters in these spaces see the Dimensions of Colour entries on lightness and saturation).

The dimensions of colour - 1.1 Colours in space (David Briggs)

Colour theory in two minutes (Stephen Westland)

Color Practice (Matias Dahl)

Interactive colour demos (Stephen Westland and Marjan Vazirian)

Munsell color chart (Android app)

Hue and Blackness/Whiteness/Chromaticness

A different set of perceived-colour attributes is employed in the popular generic classification of chromatic object colours into  pure or full colours, tints (perceptually containing white), shades (perceptually containing black) and tones (perceptually containing both black and white),  and correspondingly applied to paint mixtures according to their physical content of black and white paint components. This results in a triangular hue page in which colours are placed according to their relative proximity to pure colour (chromaticness), pure white (whiteness) and pure black (blackness).  Versions of these attributes, specifically defined in different ways, are employed in the Scandinavian Natural Colour System (NCS) and in the historical Ostwald System. 

Generic representation of the attributes of blackness, whiteness and chromaticness.