If we want to colour an object then we would generally use some sort of pigment. However, in the natural world there are a surprising number of different mechanisms for producing colour. In this book Andrew Parker looks at the variety of ways in which animals can create colours, and their uses for signalling or camouflage. Each chapter deals with a different colour of the spectrum (with ultraviolet replacing indigo), and poses a problem concerning an animal of that colour. Alternative possibilities are discussed, with the accepted solution being given at the end of the chapter. Overall it is a highly informative book, and is likely to have something of interest for all readers, whatever their current knowledge of the subject.
Throughout the book Parker looks at the evolutionary development of animal colours, and addresses Darwin's worry about the evolution of the eye - that it was too perfect. On the contrary, colour can be thought of as a way of fooling the eye.
One criticism I have of the book is that the chapters sometimes seem to lose their way. I realise that this is partly due to their structure, but I think Parker carries it too far. I wouldn't like to lose the descriptions of his field work, but one thing I wouldn't miss would be his hypothetical NanoCam - a camera that can view things at any scale. I think a simple description of what is happening would be better.