Colour photography as we know it today was introduced in 1935 with the appearance of Eastman Kodak Company's Kodachrome film, and Agfa Company's Agfacolor film the following year. Its popularity has grown steadily since then, increasing so rapidly in the past two decades that black-and-white prints are now both rare and more expensive than colour prints. This note discusses the principal types of colour photographic materials and their properties, and how to evaluate their permanence. It also presents recommendations for their long-term preservation.