This series replaces the successful "Colour Aids" series. Revised versions are being relaunched as "Colour Guides" and new titles added. Retaining the features of "Colour Aids", the guides will have added and improved features such as: expanded and updated text to provide more information; typeface condensed to provide more information in a concise format; new topics added to bring the text as up to date as possible; bolder headings to make the topics easier to find; new illustrations to help with diagnosis; and an index to make the texts easier to use.