Notes on Colour

glossary

achromatic colour
black, white or grey
advancing colour
a hue that produce the illusion of being relatively nearer to the observer
analogous colours
colours that are close to each other on the colour wheel
artists’ colour wheel
a misleading name for the painters’ colour wheel
blue
  (colloquially, blue often refers to a colour with a bias towards cyan)
bright
both light and saturated
brightness
(unfortunately) almost a synonym for luminance
brilliant
very bright—both light and fully saturated
chroma
Seesaturation
chromatic
having to do with hue and saturation as opposed to luminance. A chromatic colour is any colour other than black, white or grey. (seeachromatic and monochromatic)
CIE
Commission Internationale de l’Éclairage
CMY
cyan, magenta and yellow—the subtractive primaries
CMYK
cyan, magenta, yellow and black—the subtractive primaries with black for increased density
colour constancy
the illusion that the colour of an object remains the same when illuminated by light sources with differing colours, for example candlelight and daylight
complementary
Two colours are complementary if they produce a mid grey when they are mixed in equal quantities.
contrast
The contrast between two colours is the difference in their luminance. High contrast between text and background is essential for legibility.
CSS
Cascading Style Sheet
cyan
 
dark
low in luminance
deep
both dark and saturated
deuteranopia
an inability to distinguish green
DPI
dots per inch
extraspectral hue
a hue that is visible to the human eye but does not occur in the spectrum of visible light
green
  (colloquially, 'green' often refers to a colour with a bias towards cyan)
high key
a colour scheme or a photograph may be described as high key if it uses predominantly light colours
HLS
the hue-luminance-saturation system for characterising a colour
HSB
the hue-saturation-brightness system for characterising a colour—a modified form of the HLS system used by many computer programs
hue
the underlying colour of the colour—orange, blue-green or whatever—as opposed to its luminance or saturation
ICC
International Colour Consortium
intensity
Seesaturation
isomeric
Seemetameric
Itten
Johannes Itten
low key
a colour scheme or a photograph may be described as low key if it uses predominantly dark colours
LPI
lines per inch
luminance
a measure of how light or dark a colour is
magenta
 
metameric pair
two distinct spectral distributions that produce equal colour stimuli
monochrome
Seemonochromatic
monochromatic
varying only in luminance, not hue
monochromatic image
This term usually refers to an achromatic image (a black and white photograph or other greyscale image) but it could have a distinct hue like a sepia-toned photograph.
neutral colour
an achromatic colour or one very close to achromatic; a highly desaturated colour
Newton
Sir Isaac Newton
painters’ colour wheel
the colour wheel arranged so that complementary colours are no longer opposite each other
pale
light
pastel
both light and desaturated
pink
any colour from a light red to a light magenta
primary colours
This is an ambiguous term that suggests unmixed colours from which other colours are mixed.
protanopia
an inability to distinguish red
red
  (colloquially, 'red' often refers to a colour with a bias towards magenta)
retreating colour
a hue that produce the illusion of being relatively further away from the observer
RGB
red, green and blue—the additive primaries
shade
Adding black to a colour will decrease both the luminance and the saturation. The result is a shade of the colour.
simultaneous contrast
the optical effect in which adjacent colours influence each other, each appearing to take on some of the other’s complementary colour
tertiary colours
Seetertiary hues
tertiary hues
A tertiary hue is one that is produced by an unequal mixture of two primaries. In other words, a tertiary hue is any hue other than the primaries and secondaries.
tint
Adding white to a colour will increase the luminance and decrease the saturation. The result is a tint of the colour.
traditional colour wheel
Seepainters’ colour wheel
tristimulus colours
Seeadditive primaries
tritanopia
an inability to distinguish blue
value
Seeluminance
W3C
WorldWide Web Consortium
white balance
the adjustment on a digital camera to compensate for differences in the colour temperature of various light sources
yellow