The color gamut refers to the range of colors that a display can reproduce. It is mainly determined by the degree of overlap between the display’s native color gamut and standard target gamuts such as sRGB, BT.2020, DCI-P3, and NTSC (as shown in Figure 1). A higher overlap indicates that the display can reproduce more colors defined by the target color standard.
Figure 1
Among these, DCI-P3 is commonly used in cinema applications, while Adobe RGB is widely used in professional photography. Taking DCI-P3 as an example, the level of coverage has a direct impact on the display’s grade. Generally, the higher the coverage, the more expensive the display tends to be, as it can deliver richer and more saturated colors.
Therefore, improving color gamut coverage is one of the key directions when discussing accurate color reproduction in display technology.
Figure 2
Table 1
From the comparison results, it can be observed that when the red and blue wavelengths and the white point conditions remain nearly constant, increasing the green wavelength from 526 nm to 536 nm leads to an increase in DCI-P3 coverage.
In other words, under these conditions, green light becomes the primary factor influencing the coverage of DCI-P3. From the CIE 1931 chromaticity diagram, it can also be observed that when the green wavelength is longer, the area it covers changes accordingly (as shown in Figure 3).
Figure 3
Therefore, this article summarizes two conclusions:
- Before manufacturing an LED display, the selection of the RGB wavelengths of the LEDs will determine the color gamut coverage of the display.
- If the goal is to increase the coverage of a specific color gamut, the shape of the target gamut should first be identified on the CIE 1931 chromaticity diagram. The monochromatic RGB wavelengths can then be adjusted so that they are closer to the RGB coordinates of the target color gamut.