Their fourth book, Doors of the World, has to be regarded in this context. Emerging as it does from their well-documented investigations into architectural color, this book-the companion volume to which is Windows of the World--completes their study of a key feature of any habitat's facade. The Lenclos's study results from a research program that is both simple and logical. First, selecting sites typical of a region and armed with the knowledge that traditional settlements are built from the substrate upon which they stand, they take color samples of locally applied pigment from each architectural component of a habitat, in addition to its building materials and the structure's indigenous flora and local geology...