1
Q
Who created the CIELab colour space?
A
International Commission of Illuminiation.
2
Q
How does CIELab work?
A
- 3 numerical values for colour.
- L* = lightness 0-100 (white).
- a*= green-red.
- b* = blue-yellow.
3
Q
What is CIELab designed to do?
A
To be perceptually uniform with respect to the human visual system.
4
Q
Explain the Munsell colour system.
A
- Based on hue, value (lightness) and chroma (colour purity).
- Illustrates a 3D colour space.
5
Q
What is the Natural Colour System based on?
A
- Colour opponency.
- Developed by Hering.
- Helps to communicate colours in a way that everyone understands.
- Builds on how the human being sees colour.
6
Q
How does the NCS work?
A
- Starts from 6 “pure” elementary colours.
- Four chromatic elementary colours are Yellow, Red, Blue, Green and two non-chromatic White and Black.
- All other colours are described in terms of their degree of resemblance to the elementary colours.
7
Q
Describe the NCS colour space.
A
- 3D model.
- Includes the whole colour world and makes it possible to describe any conceivable colour percept.
- Usually shown in 2 projections - colour circle and colour triangle.
8
Q
What does the NCS colour circle show?
A
- Hue (the colour family).
9
Q
What does the NCS colour triangle show?
A
- The Nuance of a colour.
- A subtle difference in colour.
- Vertical section through the colour space.
- Base of the triangle is the grey scale from white (W) to black (S) and the apex is the maximum chromaticness (C) within each hue.
- The scales for blackness, whiteness and chromaticness are divided into 100 steps, which as well as in the colour circle can be perceived as percentages.
10
Q
How are values in the NCS expressed?
A
- In percentages in degree to blackness, chromaticness and hue.
11
Q
Name two colour systems.
A
- RAL - European colour matching system.
- Pantone - Largely standardised colour reproduction system. Allows designers to colour match specific colours in the production stage.
12
Q
What are the functions of colour?
A
- Aesthetic effect.
- Visual effect.
- Psychological effect.
