Colour Theory: Colour and contrast

How we perceive colour -->

Spectral colour = 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 percieved as a spectral colour in a continuous spectrum. The colours of similar or sufffiecently close wavelengths are often indistinguishabe by the human eye.

Our perception of colour is based on the eye recieving light that has been reflected from a surface of an object.

White Light:

cant see individual wavelengths, see as a mix of white light

interpret colour when white light is reflected of a surface.

different materials create different wavelengths 

Shorter wavelengths produce blue light, why the sky is blue. 

Everything to do with colour is based on how we see it.

Rods: conveys shade of black, white and grey 

Cones: colours

Type 1: sensitive to red-orange light

Type 2: sensitive to green light

Type 3: sensitive to blue-violet light 

When different cones are stimulated we will see different colours such as if our green cons are stimulated we will see green. The eye if folded due to the physiological response which allows the eye to see a full range of colours through the adjustments of red, green and blue. 

Spectral colour is where the eye can not differentiate between spectral yellow and some combination of red and green. The same effect accounts for our perception of cyan, magenta. Different colour modes are needed to be able to understand colour which relate to physical colour and spectral colour to do with light. 

Subjective Colour

Chromatic Value:

 - tone, hue and saturation is what is spoken about when we discuss colour, as these make up colour. Give each colour a chromatic colour, 

• neutrals created my mixing more colours together to reduce the colour values, mixture of primaries and secondaries with more white added to reduce there values. 
• complementary colours are those opposite colours on the colour wheel this is because the complementary is made by combination of two primaries. 
• Everything we see has a colour value but depends on its hue, tone and saturation which can be altered to create different colours. 

Series of Contrasts in:

Tone -->

 This 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. Contrast and tone 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. 


Saturation -->

Juxtaposition of light and dark values and their relevant saturations. The variation effects how the eye sees the shades as colours can appear lighter and darker. Tone, hue an saturation work together within the contrast of saturation to see how pure a colour is. 

Hue -->

The contrast in hue allows for colour to be recognised based on the wavelengths. Contrast of hue looks purely at the tonal value and the colours they create, closer in hue the colours, lower the contrast. 


Temperature -->

Relates to the hues that can be considered warm or cool. Oranges and reds are associated with warmth whereas blues are perceived as cold colours. The use of different tones of red can create a cooler red based on the contrasts created when they are overlapped or placed next to each other. 


After Image -->

How are eye see and perceive colour as well as the memory of the eye. When you look at something that is bright and look away you can still see aspects of the image. Eye remembers colour that it’s seeing, as information seen by rods and tons burns information into the retina. Eye seeing saturated light to the eye flips the colour in order to balance the colour.