The RGB color mode is a superposition of the three primary colors of red (R), green (G), and blue (B). Its principle is consistent with the luminous characteristics of display devices: screen pixels actively emit light to present rich colors in different intensities, especially good at expressing high saturation and high brightness colors, and can dynamically adjust the color gamut range to meet the needs of digital content creation and display.
However, printing uses the CMYK mode (cyan, magenta, yellow, and black), which relies on the reflection of ink to light to present colors. When printing, inks need to be superimposed through the principle of subtractive color mixing, and the color gamut range is naturally smaller than RGB. If RGB images are directly used for printing, bright colors that exceed the CMYK color gamut (such as fluorescent colors and pure red) will be distorted due to the inability to restore, resulting in color deviation or loss of details. In addition, RGB is an additive color mode, and the stronger the color light is mixed, the higher the brightness; while printing is a subtractive color mode, the more ink is superimposed, the darker the color, and the color logic of the two is opposite. Therefore, RGB is suitable for scenes where display devices actively emit light, but printing requires light to be reflected by ink, and needs to be converted to CMYK mode to match the physical limitations of the printing process to ensure accurate color restoration.