Lecture 11: Colour theory 2

Subjective Colour

There is no one colour red, it is a contextual thing and depends what else is around it. It may be the reddest thing we see, but it could actually have orange tones or be quite dark etc.

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 wavelengths generates monochromatic light. Every wavelength of light is perceived as a spectral colour in a continuous spectrum. The colours of similar of sufficiently close wavelengths are often indistinguishable.

Colour is a theoretical as well as a physical phenomenon, how we see it is actually an illusion.

chromatic value = hue + tone (luminance) + saturation

-Tone:

Can be seen by looking at black and white, series of colour contrast that allow different colours to be visible through the contrast which allow for differentiation. The simplest form of this Rods working out black, white and greys. Contrast allows for things to be seen easily as black and white are quite high contrast. However using tones/shades of the same colour make it more difficult to see due to little contrast. 

-Hue:

Juxtapose differs colours and identifies the greatest contrast. The contrast in hue allows for colour to be recognised based on the wavelengths.

Blue and yellow on a white background would suggest that colour has a tonal vlue because the yellow would not stand out as much as the blue. There is a higher contrast of hue with the blue on the white. The colour and tone proximity can confuse the eye and if they are too close, it make it hard for the user to know which one to read. 

-Saturation:
Formed by the juxtaposition of light and dark values and their relative saturations.
when shown a shade of blue, you may just label it as blue but then when compared to another blue it may become a 'light blue' etc. 

-Contrast of Extension
Formed by assigning proportional field sizes in relation to the visual weight of a colour. Also known as the contrast of proportion.

-Contrast of Temperature:
formed by juxtaposing hues that can be considered 'warm' or 'cool'.
Blue is seen as a cooler colour and orange is seen as a warmer colour. Adding a a tint of blue to the red would make that a 'cooler' red rather than a red with a bit of orange which would be 'warmer'.
The colour swatch of changing temperatures shows that each square does not look like one set colour, but towards the right it lightens out. This is because there is a higher contrast between the two colours, so the lighter colour will have a patch that seems to be lighter, due to this contrast.  







-Complementary contrast:
Red and green do not work together as it is too harsh on the eyes, complementary colours do not work together. harmonious contrast is nice on the eye and would make a passage of coloured text easier to read. 

-Simultaneous contrast:
Formed when boundaries between colours perceptually vibrate
When you stare at the colours they begin to change. yellow and green next to each other would make the green more blue and the yellow more orange when you stare at them.