Computer monitors can't convey all the color gamut that humans are capable of seeing. Sometimes different monitors display colors differently. Also, the number of colors displayed can vary.
In this topic, we're going to talk about how colors are formed, and the difference in the colors monitors display from all the colors we can see.
Color model
Colors can be described using a set of numbers or, in other words, color coordinates. A mathematical model for describing colors using coordinates is called a color model. It defines the principle of color formation, the units of measurement, and the boundaries of the scales.
Coordinate systems can be rectangular, cylindrical, spherical, and so on.
Classification of color models
Color models can be conditionally divided into three types:
- Additive models are usually used to produce color on a monitor. In them, new colors are obtained by adding a primary color to black. The greater the intensity of the added color, the closer the resulting color is to white. Mixing all primary colors results in white if their intensity values are maximal, and black if their intensity values are zero. An example of an additive model is RGB.
- Subtractive models are mostly used in printing. In them, the primary colors are subtracted from white to get all the other colors. The greater the intensity of the subtracted color, the closer the resulting color is to black. Mixing all primary colors gives black when the intensity value is maximal, and white when the intensity value is zero. Examples of such a model are CMY, CMYK.
- Perceptual models take into account human vision rather than the technical characteristics of the device. Their main feature is the separation of color and brightness. Examples of such a model are HSL, HSB.
Color space
Since device screens cannot reproduce the entire spectrum of possible colors, it became necessary to somehow highlight and indicate these "limitations". There is such a thing as a color space for this.
A color space defines the range of available colors in the chosen color model. For instance, sRGB is the color space of the RGB color model.
Conclusion
To summarize, in this topic you've learned what a color model and color space are. The color model defines the color gamut of human vision. In contrast, color space tells us about the color gamut available to monitors. Color models are conventionally divided into:
- Additive, mainly used to produce colors on monitors;
- Subtractive, which are often used in printing;
- Perceptual, which are based on the principles of color perception by the human eye.
Now, let's practice what we've learned.