RGB&CMYK

RGB and CMYK are different color models. When we talk about printing, these two color models need to be discussed first.

RGB color model is derived from 3 elemental colors (red, green and blue) of light that human can detect. It is an additive approach: when red, green and blue are added together white color will be generated ultimately. The application of the RGB color model is for images’ representations in electronics with display, monitor or screen.

CMYK color model is familiar to printing professionals. It is comprised of 4 colors: cyan, magenta, yellow and key (black). Cyan, magenta and yellow colors are the opposites of red, green and blue colors. Compared to the additive approach of RGB color model, CMYK color model represents an subtractive approach. The dyes, ink and pigments absorb and reduce the light that would be reflected. Ideally, cyan, magenta and yellow colors can lead to black color. However, due to the limitation of printing material, they just create imperfect black or dark grey. Black color is therefore created independently for production efficiency and that is why CMY plus K becomes CMYK color model.

One thing interesting is that many people learned RYB (ref, yellow, blue) color model when painting in school. RYB color model has very long history and its logic was widely accepted before. Nevertheless, CMY color model is deemed to have a complete gamut of colors in modern science.