- Colour is a secondary quality, a relation between light entering eye
and brain function, a construct of the mind, not a quality in objects.
(Colour is within us)
- Primary qualities are quantifiable, mathematical, and external.
Galileo (1623) The book of Nature “is written in language of
Newton (1721) “For the rays, to speak properly, are not
- Adding lights increases intensity and brightness. Adding pigments
subtracts reflected wavelengths (by expanding range of absorption)
Colour attributes – primary and secondary
- Three main physical properties along with their corresponding mental
Wavelengths: Corresponds to experiences of hue
Intensity: Corresponds to experience brightness
- Hue: the colour. Ex) Blue, red, orange, green.
- Dichromatic (colours but no red); Achromatic (black and white)
Colour vision: Opponent process
- Why do we see afterimages of complementary colours?
- Opponent-process theory (Hering 1834-1918) states that colour
wision came about from three opposing process
Black and white;