Primary colors are the fundamental hues of any color system, as they cannot be created by mixing other colors. These base colors are combined in various proportions to generate a vast spectrum of secondary and tertiary colors. The choice of which colors are considered primary depends entirely on the medium being used, whether it involves light or physical materials like paint and ink.
Identifying the Primary Pigment Colors
The three primary pigment colors are Cyan, Magenta, and Yellow (CMY). This set forms the foundation of the subtractive color model used in modern printing and color reproduction. Commercial printing often uses the CMYK model, where “K” (Key/black ink) is added to achieve deeper shadows and true black tones that pure CMY inks cannot perfectly produce.
This modern system has largely replaced the traditional art model of Red, Yellow, and Blue (RYB). While historically significant, the RYB model cannot produce the same vibrant range of colors as CMY. Using Cyan and Magenta instead of traditional blue and red allows for the creation of cleaner, more vibrant secondary colors, such as saturated green and brighter violet.
How Subtractive Mixing Works
The CMY primaries function through subtractive mixing, based on light absorption and reflection. When white light strikes a pigmented surface, the pigment absorbs specific wavelengths and reflects the others; the reflected light is the color we perceive.
Absorption and Reflection
Each primary pigment absorbs one of the primary colors of light: cyan absorbs red light, magenta absorbs green light, and yellow absorbs blue light. When two or more pigments are mixed, they collectively absorb a larger portion of the light spectrum. For example, mixing cyan and yellow results in green because the cyan absorbs red light, the yellow absorbs blue light, and only green light is reflected.
Creating Black
As more pigments are added, more light wavelengths are absorbed, or “subtracted,” from the visible spectrum. When all three CMY primaries are mixed perfectly, they theoretically absorb all wavelengths of light, resulting in the perception of black.
The Difference Between Pigment and Light
Pigment-based color (CMY) operates differently than light-based color, which uses the additive color model. The additive model uses Red, Green, and Blue (RGB) as its primaries and is found in devices that emit light, such as monitors and television screens. In the additive system, color begins with black (the absence of light). As RGB light is combined, the mixture becomes brighter; mixing all three at full intensity results in white light. This contrasts with the subtractive pigment model, where combining all three primaries results in black. The choice of primary colors—CMY for pigment or RGB for light—depends on whether the system is mixing physical materials that absorb light or mixing beams of light that are emitted.