Dyeing to Change is a comprehensive guide to the art of hair dyeing. This book will teach you everything you need to know about the process of dyeing your hair, from selecting the right color
From Wikipedia
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. Dye molecules are fixed to the fiber by absorption, diffusion, or bonding with temperature and time being key controlling factors. The bond between the dye molecule and fiber may be strong or weak, depending on the dye used.