A complementary colour is a colour of light that, when combined with a specific opposing colour in the correct proportion, produces a neutral grey or white. In photography, art, and design, understanding complementary colours is essential for colour correction, composition, and creating visual impact. Complementary colours are positioned opposite each other on the colour wheel-such as red and green, blue and orange, or yellow and purple-and are often used to enhance contrast, balance tones, and draw attention to key elements in an image.