At present, the quality of multi-color prints can be assessed both visually and using densitometry control, i.e. quantitatively. It would be impossible to imagine the quality of color reproduction without methods of precise color description in standardized mathematical expressions. In practice and scientific researches two ways of systematization and quantitative description of colors are applied. The first is the color standards method, and the second is the measurement method, or colorimetric method. In the color standards method, sets of colors are prepared in advance. The colorimetric method is based on the fact that each color has three quite defined values - the color coordinates. Color models of color description are a means of quantifying color and the differences between shades of color. There are four types of color description models. Two models are the most commonly used in practice: additive RGB, and subtractive SMUK. The RGB model takes red, green and blue as the primary or basic color. In the subtractive RGB model, cyan, magenta, and yellow are chosen as the primary colors. The purpose of this paper is to quantitatively evaluate the RGB and subtractive RGB color models. The base emissivity of both colorimetric systems were evaluated on a spectrophotometer CM 3600d. The spectral reflectance curves of the primary colors of the subtractive SMUK were evaluated. Color equations for both mathematical models have been compiled using the reflection coefficients; color envelopes have been studied using the chromaticity diagram. It has been found that additive RGB model has greater color gamut than subtractive SMUK model, i.e. color losses occur. Therefore, scanners and digital cameras, monitors and output devices should be calibrated during reproduction.