Why do printers use cyan, magenta and yellow inks?
Commercial printers use a four color printing system where a color image is separated into 4 different colors (called a color separation). This used to be done graphically with film, but now it’s usually done digitally. The resulting color separation of 4 images are sequentially printed on a printing press with the colored inks cyan (blue), magenta (red), yellow and black, which reproduces the original color image. Inkjet printers use these colors (called a CMYK process for cyan, magenta, yellow and black) in the same way to print a color image.