What is a spot color and what are four colors: a spot color refers to a specific color. When a spot color is printed, it is not a color synthesized by printing C, M, Y, and K four colors, but a special color. Specific inks to print colors. Spot color inks are pre-mixed by the printing house or produced by the ink house. For each spot color of printed matter, there is a special color plate corresponding to it when printing. Use spot colors to make colors more accurate. Such as: special gold, special silver, etc. Four colors refer to the printing colors in CMYK mode.