This textbook provides an analysis of the current state of science in the field of light theory, describes the mechanism of photoprocesses occurring in the structure of various materials during their natural aging. Mechanisms of other optical phenomena are presented, such as processes of color formation or color perception of the surrounding world by both organs of vision and devices. The textbook introduces the reader - a student of an artist, a future restorer or an expert in the field of art - with various color models describing color in coordinate spaces, and with methods for finding compatible dyes for color matching in order to get the desired color. The text of the book is presented at a sufficiently high scientific level, but it is presented in a language understandable for students of humanitarian areas of training .. The training manual is intended for bachelors and master's students , Students in this field of study, as "Commodity Studies" , Theory and History of Art , "Decorative-Applied Art and Folk Crafts" , "Restoration" , as well as in all other specialties in the field of art criticism, and can be used in the study of disciplines "Stabilising painted materials" , "Color and its formation on surfaces" , "Coating materials" , "Colour in Art" (CM) "Toning in the restoration" .