This article may be too technical for most readers to understand.(November 2023) |
The Color Naming System (CNS) is a systematic notation for named colors for computer applications using English terms created by Berk et al. in 1982. [1]
CNS uses ten color names, three of which (black, white, gray) are special, and has them combined or prefixed with several modifiers.
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The system expressed in Backus–Naur form looks something like this:. [2] [3]
named-color := gray-color | chromatic-color
gray-color := 'black' | 'white' | lightness gray
gray := 'gray' | 'grey'
chromatic-color := [ tint | shade ] hue | [ lightness | saturation ]? hue
tint := 'whitish' | 'pale' | 'brilliant' | 'vivid'
shade := 'blackish' | 'dim' | 'deep' | 'vivid'
saturation := 'grayish' | 'moderate' | 'strong' | 'vivid'
lightness := 'moderate' | 'very'? [ 'dark' | 'light' ]
hue := splash-color? base-color | base-color '-' base-color
base-color := 'red' | 'orange' | 'brown' | 'yellow' | 'green' | 'blue' | 'purple'
splash-color := 'reddish' | 'orangish' | 'brownish' | 'yellowish' | 'greenish' | 'bluish' | 'purplish'
There have been variations of the CNS proposed for inclusion into CSS that are more compatible with existing schemes. [4]
color := [saturation || lightness || transparency] hue
saturation := absolute saturation-value | saturation-value relative
saturation-value := 'dull' | 'bright'
lightness := absolute lightness-value | lightness-value relative
lightness-value := 'dark' | 'light'
absolute := [modifier '-']?
modifier := 'extra' | 'semi'
relative := 'er'
transparency := ['semi-']? opacity-value
opacity-value := 'opaque' | 'transparent'
hue := prime | general | special
prime := 'red' | 'green' | 'blue' | 'cyan' | 'magenta' | 'yellow' | 'white' | 'black'
general := 'navy' | 'lime' | 'teal' | 'aqua' | 'maroon' | 'purple' | 'fuchsia' | 'olive' | 'gray' | 'silver'
special := extra | composite ; composite ≈ prime '-' prime
extra := 'pink' | 'brown' | 'tan' | 'orange'
composite := 'yellow-green' | 'green-cyan' | 'cyan-blue' | 'blue-magenta' | 'magenta-red' | …
ISCC-NBS System - a competing color naming system