Colour mixing is the practical process of combining colours using either additive or subtractive colour synthesis to create a wide range of hues. In additive mixing, light sources such as red, green, and blue are combined to produce new colours, commonly used in digital displays and stage lighting. In subtractive mixing, pigments or inks like cyan, magenta, and yellow are combined, as in printing or photographic processes, to produce the desired colour. Understanding colour mixing is essential for photographers, designers, and artists to achieve accurate colour reproduction, create visually appealing compositions, and control mood and emphasis in their work.