Complementary colors the complementary wavelength to produce a neutral color (gray or white). Color printing, like painting, also uses subtractive colors, but the complementary colors are different from those used in painting. As a result, the same logic applies as to colors produced by light. Color printing uses the CMYK color model, making colors by overprinting cyan, magenta, yellow, and black ink. In printing the most common complementary colors are magenta–green, yellow–blue, and cyan–red. In terms of complementary/opposite colors, this model gives exactly the same result as using the RGB model. Black is added when needed to make the colors darker. The
RG color space replicated accurately in the RG color space. There is a similar color space called RGK which also has a black channel. Outside of a few low-cost high-volume applications, such as packaging and labelling, RG and RGK are no longer in use because devices providing larger gamuts such as RGB and CMYK are in widespread use. Until recently, its primary use was in low-cost light-emitting diode displays, where red and green tended to be far more common than the still nascent blue LED technology, though full-color LEDs with blue have become more common in recent years. ColorCode 3-D, a stereoscopic color