Colour synthesis is the process of combining different coloured lights or dye layers to create a full-colour image. In additive synthesis, red, green, and blue light sources are combined to produce a wide range of colours, as seen in digital screens and projectors. In subtractive synthesis, cyan, magenta, and yellow dyes are layered to reproduce colours in printing and photographic materials. Understanding colour synthesis is essential for photographers, printers, and digital artists to achieve accurate colour reproduction, vivid tones, and visually compelling images.