Additive colour printing is a photographic and printing process that combines varying intensities of red, green, and blue light to create a full spectrum of colors on color-sensitive printing paper. By layering these primary colors, the process reproduces realistic hues and tonal variations in photographs and prints. Additive colour printing is fundamental to digital imaging, projection systems, and certain traditional photographic techniques, allowing photographers and printmakers to achieve accurate color reproduction, vibrant images, and creative effects. Understanding additive color principles is essential for color correction, printing workflows, and high-quality image production.