COP Lecture 10- Colour Theory

> Questioning colour itself
> How do we know this apple is red?
> Colour is contextual and dependant on its surrounding
> However designers work with isolated colour and we need to consider its appearance in context/ when surrounded by colour.
> Spectral colour is a colour that is evoked by a single wavelength of light within a visible spectrum.
> A single wavelength, or narrow band of wavelength generates monochromatic light
> Every wavelength of light is perceived as a spectral colour in a continuous spectrum.
> The way we perceive colour is from reflection of light off of a surface or an object.
> White is a highly reflective colour
> The sky is not blue, it is pure white light. The short wave lengths reflect off of articles and blue is reflected
> The eye contains 2 kinds of receptors
- rods and cones
- rods = convey shades of black, white and grey
- cones = allow the brain to perceive colour

- 3 types of cones:
1, sensitive to red/ orange light
2, sensitive to green light
3, sensitive to blue light

> A combination of 2 cones = a different colour
> the only colours we actually see are red, green and blue. Different colours are made up of different proportions of these colours.

> Joseph Albers and Johannes Itten are both iconic influences of colour theory

>Primary colours: red, blue and yellow
> complimentary colours,
red and green
yellow and purple
blue and orange
when mixed together they cancel each other out, this is called a neutral.

> spectral colours, the eye cannot differentiate between spectral yellow and some combinations of red and green. The same effect accounts for our own perception of CMYK

> Colour modes:
> RGB, usually screen based
> CYMK, for printing
[2 different ways of perceiving colour]

> Subtractive colour systems, subtract colour values
> Additive colour systems, add more colour which creates white light
>Chromatic value =
Hue, Tone and Saturation

Hue is  the colour itself, our initial response to a colour, the way we recognise and describe it
Luminance is how bright the colour is
Shade is how dark the colour is
Tint refers to adding more white therefore how light the colour is
Sint is a combination of shade and tint