Colour Attributes

Several broad categories which are used to sort, order and describe a colour’s appearance. The terms character & hue family can be used to broadly describe a colour’s appearance. More specific sets of attributes include: hue, lightness/value & chroma; and hue, whiteness & blackness; and hue, brightness & colourfulness. Note that different systems or frameworks for colour categorization may use different but related concepts to specify the various colour attributes (e.g. chroma and saturation are related concepts, but do not mean exactly the same thing).

• Simple definition: Words that we can use to fully describe how colours appear.

• Example: Although we may use the term ‘green’ to describe the colours shown in the large rectangle below, the visual quality of the green varies throughout the rectangle.

The 3 squares at the bottom may be simply described as pale green, dark green and vivid green, or described in more detail using one of the sets of colour attributes.

• Expanded discussion: available at David Briggs’ Glossary: Basic Colour Attributes

Definitions of some sets of colour attributes

1) Hue Family & Character

Hue family: A group of colours that can all be categorized as having the same hue, no matter what their other colour attributes are. Each hue can be described with many variations: Vivid, Pale, Dark, Muted, etc. The figure depicts a useful introductory set of nine hue families, which are clearly differentiated, familiar and easy to name.

Character: Character is a term for the aspect of a colour, in addition to its hue (or hue family), used to fully describe its appearance. Colours can be grouped in broad categories, such as pale, dark, muted, and vivid.

2) Hue, Lightness/value & chroma

Hue: Hue is one of the perceptual attributes of colour, and is the most prominent quality by which we distinguish one colour from another, i.e. red, yellow, orange, green, blue, magenta, etc.

A colour’s hue is found by determining the most similar colour in the continuous circuit of vivid colours passing through red, yellow, orange, green, blue, magenta, and their intermediate colours. Hue sequences are often presented as a colour wheel, with the order of colours around a colour wheel is the order of colours seen in the spectrum, plus non-spectral hues to complete the circuit.

Note that sometimes the term ‘colour’ and ‘hue’ are used interchangeably, but hue is only one of colour’s attributes, and is not enough to fully describe a colour’s appearance. See the common misconception that discusses why colour and hue do not mean the same thing.

Note that the most vivid example of a hue is often chosen to represent the hue, although all members of a hue family will have the same hue. Also note that it is preferable to refer to hues in plural – there is not a single red hue but rather many red hues. Finally, note that colours have hues; colours are not hues.

Lightness/value: The attribute of colour which describes how light or dark a colour looks, compared to for example the greyscale which runs from light (white) to dark (black). It is used to describe colours of objects rather than colours of lights.

• Simple definition: Ways to describe how light or dark a colour appears.

• Expanded discussion: Available at David Briggs’ website The Dimensions of Colour: Lightness

• Example: Figure A below depicts a painting in full colour, and Figure B shows the lightness/value information, leaving the hue and chroma information in Figure C.

Chroma (related terms: saturation, purity, intensity): A measure of the vividness of a colour, judged relative to an achromatic grey of the same lightness/value.

Chroma is related to the terms saturation and purity, used in some colour ordering systems, but does not mean precisely the same thing. From the Greek khroma, colour. Note that the term ‘colourfulness’ is often used to describe the vividness or chroma of a colour in everyday language. However, the term ‘colourfulness’ has a precise definition as a formal scientific concept.

• Simple definition: How vivid or muted a colour looks. (Or, how close to a grey of the same lightness a colour looks.)

• Expanded discussion: Available at David Briggs’ website – The Dimensions of Colour: Chroma

• Example: The swatches on the left have higher chroma than the ones on the right.

3) Hue, whiteness and blackness

Hue: See definition above.

Whiteness: The degree of resemblance to the perception of pure white.

Blackness: The degree of resemblance to the perception of pure black.

In the figures below, the figure on the left shows a hue plane indicating colours with increasing blackness, and the figure on the right shows a hue plane indicating colours with increasing whiteness.

Left: Hue plane indicating colours with increasing blackness. Right: Hue plane indicating colours with increasing whiteness. Images courtesy of Paul Green-Armytage

4) Hue, brightness and colourfulness

Hue: See definition above.

Brightness: The perceived amount of light emitted, transmitted or reflected by an object.

Note that the term ‘bright’ is a term often used in everyday language to refer to the vividness or vibrancy of a colour, however the term ‘brightness’ has a precise definition as a formal scientific concept, as given here.

Colourfulness: The perceived chromatic intensity or vividness of the light emitted, transmitted or reflected by an object. Note that the term ‘colourfulness’ is often used to describe the vividness or chroma of a colour in everyday language. However, the term ‘colourfulness’ has a precise definition as a formal scientific concept, as given here.

• Example: In the image of the banana, the right side of the banana appears brighter than the left side. The right side appears to reflect more light than the left. The right side of the banana appears also appears more colourful than the left side. However, the set of colour attributes of the whole banana specified by its measured hue, lightness and chroma, is the same throughout the entire banana.

Expanded discussion: The painted strip is perceived to have a uniform red colour belonging to it throughout (called its object colour) but is also perceived to reflect more light, and more colourful light, in its upper portion. This difference in brightness and colourfulness is perceived to depend on the relative illumination rather than to be a change in the painted strip itself.

FIND OUT MORE:

David Briggs, The Dimensions of Colour: Brightness and Colourfulness