“I see trees of green,
Red roses, too.
I see them bloom,
For me and you!
And I think to myself:
What a wonderful world!”

We all live in a world where colour affects us in our daily lives. Colour in everyday life is very diverse, from knowing that a fruit is ripe to eat, to understanding how colour can affect our moods.

What is colour?

Colour is simply light of different wavelengths and frequencies. Imagine light travelling in waves like those in the ocean. It is these waves that have the properties of wavelength and frequency. Each colour has its own unique wavelength and frequency. For example, the colour red has a much longer wavelength than the colour violet, so each violet wave would span a much shorter distance.

How do we see colour?

The retinas in our eyes have three types of colour receptors in the form of cones. Although there are seven main colours on the visible spectrum, we can actually only detect three of them. These visible colours are red, blue and green, and these three colours are mixed in our brain to create all of the other colours we see.

Where does colour come from?

Colour simply comes from light, sunlight being the main source of colour. Using a prism, we can 'extract' the colours from white light – i.e. sunlight. When light from the sun passes through a prism, the light is split into the seven visible colours by a process called 'refraction'. When we see a rainbow after a thundershower, what we are seeing is the sun shining through the raindrops which perform the function of a prism, refracting the light.

How do we use colour in our daily lives?

Colour is an element of visual language that people process before they are consciously aware of it, and is a powerful element of visual communication.

1. Colour coding often speeds up visual search; it is a way to convey visual information quickly. An example is the different colour- coded lines on a map of train routes, which are represented by different colours.

2. Colour helps with object recognition. We recognise objects more quickly when their colours reflect what we see in the physical world. For example, a purple banana would take us a while to recognise!

3. Colour is used to convey or enhance meaning. Our brains constantly seek to make sense of what we see and to assign meaning to it. Because the eyes are attracted to bright colours, these are interpreted as representing something of value; it is as though the object is shouting to be noticed and valued! Think about how this works in advertising.

4. Colour can be used to convey structure, for example each chapter heading in a textbook may be a different colour, or sections in a supermarket may be colour-coded according to products.

5. In marketing and advertising, colour is used to establish identity. Cell phone companies, for example, use this constantly, and we instantly recognise a brand by its colour often before we identify it by name.

6. Colour elicits psychological associations that symbolise both ideas and feelings. The perception of colour is subjective and has cultural implications, but some colours do have universal meaning. The warm colours, i.e. red, orange and yellow represent warmth and comfort, but can also be seen to mean anger and aggression. Blue, green and purple, the cool colours, range from feelings of calm and tranquillity to sadness and despair. Black is often seen as representing death or evil, but in Ancient Egypt stood for life and rebirth. White is associated with purity and innocence, but can also be seen as emptiness. Brown is a natural colour, the colour of warmth and comfort.

7. As well as being associated with feelings, colour is often used to create mood. Lighter colours generally have a more positive effect, while darker colours evoke a more negative mood. Painters use the different hues of colours effectively to create mood. 8. We even use colour in spoken language, for example we may “feel blue”, be “green with envy” or “see red”. These are used in literature as well as in our everyday conversations.