280 A DICTIONARY OF COLOUR
n optical colour
The technique (widely used by the Impressionist school of artists) of painting broad
bands, blotches or spots of colour next to each other so as to create an illusion
in the brain of the viewer of a third or extra colour when the work is observed
from a distance. Also called divisionism. A similar and more startling effect can
be obtained from computer-generated 2-dimensional colour designs which when
studied carefully appear to transform into a 3-dimensional image having a new
(and more luminous) colour. Another example occurs with the blending of colours
on a spinning colour circle. See also Pointillism.
n optical fibres
Conduits as thin as human hair through which infrared light can travel at speed
without degradation and with many applications including telecommunications,
in particular, the Internet.
n Optical Stimulated Luminescence (OSL)
A new technology used by archeologists to determine when soil was last exposed
to sunlight.
c or
In heraldry, the colour gold or yellow.
c orange
The colour of the fruit, orange, when it is ripe. (The orange was previously called
a ‘narange’ – an adaptation from the Spanish ‘naranja’ or ‘naranj’. There are
several English words from which the initial ‘n’ has been dropped, by way of
a process known as aphesis including ‘apron’ which was formerly ‘napron’ and
‘adder’ which evolved from ‘nadder’. The change works in both directions, for
example, ‘nickname’ originates from ‘ an eke name’ (an additional name)). Orange
covers a wide variety of colours in the range of approximately 630 to 600 nanome-
tres.The colour of William of Orange and of the Ulster Orangemen; the colour
of goldfish and of Penguin Books from 1935. Orange is one of the few colours
(see also violet) which does not have a rhyming word thus giving rise to Willard
R. Espy’s Procrustean rhyme in Words to Rhyme With – A Rhyming Dictionary
– MacMillan 1986, ‘The four eng,- ineers, wore orange, brassières’.
c Orange
One of the 140 colours in the X11 Color Set. It has hex code #FFA500.