Design Principles: Colour theory part 1

AN INTRODUCTION TO COLOUR THEORY

The range of colours the human eye can see

In this lesson we were introduced to colour theory. I learnt a lot about how we perceive colour, and how we can all see colour very differently depending on how our eyes work. 25% of the world's population is colour blind. 

Colour is actually much more important in graphic design than I thought, especially typography. It effects how legible and readible letters and words are. The type below is incredibly illegible and hurts to look at because of the clash of similar colours.

But when the same type is put on a white background, it suddenly becomes very calming and easy to look at and read.

However, it still isn't as legible as you would like, as the lilac colour is very pale. 

The text above is even more legible, but very bright and not completely pleasant to read, so the readability isn't at the same level as the legibility. 

These combination of colours are the most satisfying to read in terms of legibility and readability. The image below is incredibly hard to look at because the level of contrast is too high.

These combinations of colours have different effects because of how our eye and brain perceives them. The colour may be changed along the way. As seen above, there are three stages:

• physical - the literal colour of an object
• physiological - how our eye picks up the colour
• psychological - how our brain perceives what our eye has seen

This is how many people handle colour in different ways. 

The eye contains two kinds of receptors:

Rods convey shades of black and grey

Cones allow the brain to perceive colour

There are three different types of cones:

Type 1: sensitive to red-orange light

Type 2: sensitive to green light

Type 3: sensitive to blue-violet light

When the green cones are stimulated, we see green.

When the red-orange cones are stimulated, we see red.

When both the green and red-orange cones are simultaneously stimulated, our perception is yellow.

Because of this physiological response, the eye can be fooled into seeing the full range of visible colours through the proportionate adjustment of just three colours: red, green and blue.

As seen above, many people suffer from different cases of colour deficiencies. This can completely change the colours they perceive. Because of this, graphic designers have to be aware of how some people may perceive their designs in the completely wrong way. 

Josef Albers (1888 - 1976) and Johannes Itten (1888 - 1967)

These men were both early colour theorists. 

Johannes Itten's colour wheel 

From this colour wheel you can see which colours compliment each other, depending on if they are opposite each other on the colour wheel. For example, violet and yellow compliment each other. These same colours also cancel eachother out when mixed together:

Above is a tertiary wheel. It shows the neutral versions of the colours on the original colour wheel.

Spectral colour: a colour that is evoked by a single wavelength of light in the visible spectrum or by a relatively narrow band of wavelengths.

The eye cannot differentiate between spectral yellow, and some combination of red and green.

The same effect accounts for our perception of cyan, magenta, and the other in-between spectral colours. 

RGB/CMYK colour modes

When CMYK colours overlap they show the secondary colours for RGB. When the RGB colours overlap, the result is the CMY colours.

Additive colour: colour created by mixing light of two or more different colours. Red, green and blue are the additive primary colours that are normally used in additive colour systems. The light that is added is reflected off a surface or will be picked up by the viewer's eyes eg when looking at a computer screen.

Subtractive colour: colours are created by subtracting parts of the spectrum of light present in ordinary white light, by means of coloured pigments or dyes (such as those in paints or colour photographs on film). This is why it is ideal for printing.

DIMENSIONS OF COLOUR

Chromatic value = Hue + Tone + Saturation

HUE:

LUMINANCE:

Shade, tone and tint

Colours are classed as certain colours depending on what OTHER colours they are next to.

Pantone colours are very systematic and are a very successful guide when choosing which colours to use in graphic design.