Shades of cyan are blue, green, and red.) As such, the CMYK printing process was invented in the 1890s, when newspapers began to publish color comic strips. Process cyan is not an RGB color, and there is no fixed conversion from CMYK primaries to RGB. Different formulations are used for printer's ink, so there can be variations in the printed color that is pure cyan ink. A typical formulation of "process cyan" is shown in the color box at right. The source of the color shown at right is the color magenta that is shown in the diagram located at the bottom of
Secondary color Secondary color A secondary color is a color made by mixing of two primary colors in a given color space. For the human eye, good primary colors of light are red, green, and blue. Combining lights of these colors produces a large range of visible colors. That is, the primary and secondary RGB colors (with secondary colors in boldface) are: Combining RGB colors means adding light (thus the term "additive color"), and the combinations are brighter. When all three primaries are combined in equal amounts, the result is white. The RGB secondary colors produced by the addition of light turn