This introductory chapter first sets out the aims of the study reported in this book, viz. to examine in detail the use of colour terms in the poetry of Dylan Thomas. We stress that the study is primarily linguistic rather than literary, and that we do not engage with the voluminous critical and biographical literature on Thomas except where we find references to colour usage. Rather, our main aim is to provide a description of every use of a colour term in the five main sets of Thomas poems and to examine the use of colour terms in relation to the symbolic connotative associations between colours and other domains which are often included in discussions of ‘colour semantics’ and form the basis for what have been referred to as colour metaphors. We trust that this study will contribute to the deeper understanding of Thomas’s creative language powers, in particular his very individual exploitation of cultural connotations of colours to evoke images and emotions in the reader’s mind. We further intend the rich database of these connotative associations to be of use to researchers who may be interested in the use of colour terms in other texts, whether literary or non-literary. Our study is both qualitative and quantitative. We give an illustrative list of questions to which we aim to provide answers. The chapter goes on to describe the structure of the book in terms of the five parts into which it is divided and the chapters contained in each part, with a brief statement of the content of each chapter.