Lightness and Brightness and Other Confusions

Inherent, identity and nominal colour
There is an increasing need in industry, commerce and design for measuring
and designating colours accurately. Both physical and visual measuring tools
and methods have been developed to answer these needs. While these tools
have attained a remarkably high degree of accuracy, one challenge remains:
relating the measuring data or the visual sample of a colour to the human
experience of that colour in real life or in a specific context of real life. This is
no easy task and therefore it is important to differentiate between methods
and tools that actually try to measure or define the ‘real’ colour from those
that – at first hearing – may seem to do so, but in actual fact make no such
claim. In the following is a comparison of some of these approaches and their
terminologies as well as a suggested new concept that in our view helps to
clarify the differences.
One attempt to determine visually the ‘real’ colour of physical objects was
made by Anders Hård. In connection with his work on developing the NCS
system he put forward the interesting concept of inherent colour. In The
Swedish Institute of Standards edition SIS 1993, 2.6 the terms inherent colour,
body colour and local colour have been offered as translations of the
Swedish word and concept “egenfärg”, which translates more literally into
English as (an object’s) “own colour”. The word inherent is given in the Concise
Oxford Dictionary as “existing in or in something esp. as permanent or
characteristic attribute…” This definition echoes in Hård’s defintion of inherent
colour: ”… the colour that one imagines as belonging to a surface or a
material, irrespective of the prevailing light and viewing conditions”. (Hård &
Svedmyr 1995, p 215; quoted in Fridell Anter 2000, p 25). Hård´s idea that
the inherent colour exists, but is never as such perceived is very similar to the
concept of the NCS elementary colours, which also exist, but cannot be seen
or depicted.
Hård´s definition does, however, also include a method for operationally
determining the inherent colour, which obscures the notion of an imagined
’real’ colour: “... it can be operationally determined e.g. through comparison
with a standardised colour sample.” (Ibid.) Here Hård in effect refers to the
standardised viewing conditions under which the NCS samples are perceived
to correspond with their codes. 91 Hård suggests that the colour perceived
under these conditions is equal to the ’real’ colour. This, however, excludes
the complexity of visual interrelations that are always present in real life
situations.
In her doctoral thesis What colour is the red house? Karin Fridell Anter has
used Hård’s term inherent colour in a meaning different to the above. Inher-
The standardized viewing conditions are defined under the Swedish standard Svensk
standard SS 19104, NCS-färgprover - Betraknings- och mätvillkor samt toleranser
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