CMYK color model of the primaries: cyan and yellow produce green, cyan and magenta produce blue, yellow and magenta produce red (these subtractive secondary colors correspond roughly to the additive primary colors), plus layering all three of them resulting in black. With halftoning, a full continuous range of colors can be produced. To improve print quality and reduce moiré patterns, the screen for each color is set at a different angle. While the angles depend on how many colors are used and the preference of the press operator, typical CMYK process printing uses any of the following screen angles: The "black" generated by
Shades of blue system are the three colors of light chosen such as to provide the maximum gamut of colors that are capable of being represented on a computer or television set. This color is also called color wheel blue. It is at precisely 240 degrees on the HSV color wheel, also known as the . It is a spectral color which lies at, or near, the short-wave (violet) end of the traditional "blue" and possibly was classified as "indigo" by Newton. Its complementary color is yellow. The color defined as "blue" in the CMYK color system used in printing, also known as