Beauty is more than skin deep. In nature, colour is more than a source of beauty; it’s a form of vital communication. Depending on the situation, colour says different things – it can be an expression of power or seduction, warning or deceit – and it can even, occasionally, save your life. Accompanying a major new BBC series with David Attenborough, ‘Life in Colour’ explores the fascinating story of how colour works in the natural world. From the ‘trichromatic’ vision of Silver Leaf Langurs, which allows them to see orange and red against forest foliage – the colours not only of ripe fruit, but of their young – to African Mandrills who use their colouration to do battle, Professor Martin Stevens reveals a complex system of messaging visible only to those who know the code.