Of course, in the bigger picture, the life of telecoms companies and fizzy drinks is limited. So, at some time in the not too distant future, the associations between these particular colours and products will have been forgotten or, if remembered, they will be considered quaint. A few cultural historians may even ponder over them. Yet, the reason that these colour associations exist is simple – they are created by a very small number of people in an attempt to persuade a very large number of people to buy one particular product rather than another that is more-or-less equivalent. If – by luck or by judgment – they are successful, then the colour association endures until the product is re-branded or falls from favour.

As a result, we now expect to be able choose a particular coloured item from a range of otherwise identical items. We can buy cars, for example, in an astonishing array of colours. The multitude of coloured cars may brighten-up the urban landscape, but each of them will inevitably end up as scrap whilst the concrete and tarmac roads they require spread relentlessly in monotonous shades of grey.

However, colour can only be used in an arbitrary fashion when existing colour associations are absent or weak. Are there relatively few green cars, for example, because green is still an ‘unlucky’ colour? And is green unlucky because a 19^th century green was made from arsenic, poisoning thousands, allegedly including Napoleon? Such questions remain open and colour associations keep changing; green, for example, now also signifies ‘ecological’. The associations that exist for particular colours are too fluid and often too personal to have a recognised place in the rigid and impersonal modern world, where they are instead dismissed as subjective or unreliable if not outright frivolous. Unless it helps shift a product or has a tangible purpose, controlling traffic for example, colour is treated as if it really doesn’t matter.

Yet at a personal level, we know that colour does matter. We choose colours for our homes carefully and we spend time, effort and a significant amount of money decorating and re-decorating. Our sensitivity to the subtlest nuances of colour is demonstrated by the fantastic range of cosmetics that are available, from lipsticks, through skin creams, hair dyes and much more. Some of us choose colours with confidence and others, who might be less sure about their judgement, employ willing professionals to help select the appropriate shade with which to decorate their homes or themselves.

In spite of our investment of time and money, the way we treat colours in the modern world collectively devalues our whole experience of them. Next year’s fashions will be different, so if the colour of something has any significance whatsoever, then its meaning is fleeting. Colour has been turned into an ephemeral commodity. And having been encouraged to take the colour of man-made things as merely conventional or an interchangeable add-on, it is very hard for us to imagine a world where colour had significance in its own right.

We might know little or nothing about the chemicals that colour our cars, clothes, cosmetics or even our food, but this state of affairs is quite recent. Consumers in the middle ages knew where their colours came from and what they meant. Whether of animal, vegetable, mineral or artificial origin, colours had stories to tell that touched all members of society. For millennia, colour was not just another variation in manufactured products. It was profoundly meaningful. Each colour had numerous values associated with it, and those values were coherent, stable and widely known.

Colour is a profoundly beautiful part of the sensuous world but, over the last three hundred years, its deeper significance has gradually been forgotten and our world has become poorer as a result. It is possible to reclaim the richness that colour once possessed, but this requires quite a radical change of outlook. Rescuing colour from the limbo of arbitrary associations and subjective status involves treating it as a meaningful and objective phenomenon. After all, we can’t reasonably expect colour to reveal its full glory to us if we don’t pay it some respect. It is not difficult to rediscover colour’s forgotten dimensions – all we need to do is recognise the ways that we habitually treat colour and then make some choices.

First, there is a tendency to treat colours as if they are interchangeable. We behave as if colour is not necessarily connected to something’s function. In theory, of course, we still know that the colour of fruit tells us about its ripeness, but we don’t see many green oranges in supermarkets. In practice, we know that some citrus fruits are orange and some telecoms companies are represented by the colour orange, but we don’t expect there to be any real connections between the two. We accept that no really important connections are likely to exist between things based on their sharing the same colour. (Of course, connections based on colours are real and important for the fashion industry or for football fans, but they have well-defined sell-by-dates or are little more than local membership signs.)

Second, we have a habit of treating colour as if it is instantly accessible. Colour would not work in fashion or in football if we could not instantly tell that someone was wearing this or last season’s colours or was supporting our team or the opposition. And branding with colours would not work if we had to spend time studying products in supermarkets. We expect that whatever colour has to offer us is there for the taking, with little or no effort.

A fragmented and instantly accessible phenomenon, with arbitrary associations and a subjective status, can only have limited cultural impact. But other cultures treat colour differently, and one of the most accessible cultures to have a different attitude to the subject is not many miles away – it is the medieval world, the culture that sowed the seeds of our modern sensibilities. C.S. Lewis’ The Discarded Image showed how the medieval model of the world shaped European literature and this book explores the same model to re-establish a lost relationship with colour. Each successive chapter tries to get deeper and deeper into the mind set of pre-modern or medieval Europe. Each chapter is devoted to just one colour, giving the respect it deserves and acknowledging its significance to life in the traditional world.

Most traces of the historic use of colour have gone, but the obvious survivors are the great paintings that helped shape the way we see the world today. For the people who commissioned and who created those paintings, dyes, pigments and metals were materials with their own intrinsic values as well as sources of colour. What a colour meant inside a painting depended upon what it meant outside the painting. The following chapte...