A woman goes to her bank manager for a personal loan to buy a car. Seeking to make conversation while completing the documentation, the loan officer asked his client what kind of car she intended to buy. With little interest in, or knowledge of, car makes and models – a friend having identified a suitable used car for her – the client replied, ‘Um … well … a green one.’ The colour of a car is by no means unimportant: navy blue needs washing more often than other colours; black can trap the heat in summer; grey can be hard for other motorists to see; and so on. But the colour of a car will not affect its performance and reliability.