What is RGB and CMYK? Complete Guide to Color Models

How it works: RGB creates colors through light addition. It starts with black (no light) and creates various colors by mixing different intensities of red (Red), green (Green), and blue (Blue) light.

A simple analogy: Imagine a dark room with three flashlights, each covered with red, green, and blue colored filters.

• When you turn on only the red light, you see red.
• When you overlap red and green light, you get yellow.
• When all three lights overlap, you get the brightest white.

How it works: CMYK creates colors through ink absorption. It starts with white (such as a white sheet of paper) and, when ink covers the paper, it subtracts (absorbs) certain colors from white light and reflects others. What we see is the reflected color.

A simple analogy: Imagine you have a white sheet of paper and a box of transparent watercolors (cyan, magenta, yellow).

• When you apply cyan ink, it absorbs red light and reflects blue and green light, so you see cyan.
• When you apply yellow ink, it absorbs blue light and reflects red and green light, so you see yellow.
• When you mix cyan and yellow ink together, cyan absorbs red and yellow absorbs blue, leaving only green light reflected, so you see green.

Theoretically, mixing 100% cyan (C), magenta (M), and yellow (Y) should produce black. However, in reality:

• Due to ink impurities, mixing the three only produces a muddy dark brown or gray-black.
• Using three inks to print text and dark shadow areas is wasteful and can cause paper to become too wet and misregistration.
• Using a separate black (Key plate) ink solves these issues—it's more economical, cleaner, and sharper. This is the origin of "K," which stands for Key Plate, typically referring to the black printing plate in printing.