As designers, most of us are familiar with CMYK and RGB. CMYK stands for cyan, magenta, yellow, and black (the K actually stands for Key meaning the key plate that aligns the color but modern printers do use the color black). RGB stands for red, green and blue. We also know that the colors on screen are RGB, but the printer uses CMYK.
We know these facts, but do we actually know why these conflicting color combinations exist? The key to understanding the conflict is knowing your screen projects light, whereas ink on paper is contingent on light bouncing off of the paper. Without light, our eyes would be incapable of perceiving color.
RGB color combination shows color by adding light. This is called additive color. When red, green, and blue are combined, it creates the color white. It’s like a white light refracted in a prism. CMYK color combination shows color by absorbing light. This is called subtractive color. When cyan, magenta and yellow are combined on paper, it creates the color black. It’s like when mixing these colors together on a canvas, you get a dull brownish black color.
So therein solves the mystery of why we must have the headache of different color combinations from screen to print. Matching your colors perfectly is a subject for another blog post.