Colour saturation refers to the purity or intensity of a colour in an image, determined by the absence of black, white, or gray mixed with it. Highly saturated colours appear vivid and vibrant, while low saturation produces muted or pastel tones. In photography, controlling colour saturation is essential for creating mood, emphasizing subjects, and enhancing visual impact. Photographers can adjust saturation through camera settings, lighting, filters, or post-processing software to achieve the desired artistic effect and ensure accurate, appealing colour reproduction.