Green or yellow and cyan; in the RGB color model, used on television and computer screens, it is one of the additive primary colors, along with red and blue, which are mixed in different combinations to create all other colors. On the HSV color wheel, also known as the , the complement of green is magenta; that is, a color corresponding to an equal mixture of red and blue light (one of the purples). On a traditional color wheel, based on subtractive color, the complementary color to green is considered to be red. In additive color devices such as computer displays
Color printing are variously used in printing, the result should be a reasonable reproduction of the original, but in practice this is not the case. Due to limitations in the inks, the darker colors are dirty and muddied. To resolve this, a black separation is also created, which improves the shadow and contrast of the image. Numerous techniques exist to derive this black separation from the original image; these include grey component replacement, under color removal, and under color addition. This printing technique is referred to as CMYK (the "K" stands for "key", a traditional word for the black printing plate). Today's