CMYK color model spot colors (such as metallic inks), and finishes such as varnish, which enhances the glossy appearance of the printed piece. CMYK are the process printers which often have a relatively small color gamut. Processes such as Pantone's proprietary six-color (CMYKOG) Hexachrome considerably expand the gamut. Light, saturated colors often cannot be created with CMYK, and light colors in general may make visible the halftone pattern. Using a CcMmYK process, with the addition of light cyan and magenta inks to CMYK, can solve these problems, and such a process is used by many inkjet printers, including desktop models. Comparisons between RGB
Shades of magenta a single wavelength. Humans, being trichromats, can only see as far as 380 nanometers into the spectrum, i.e., as far as violet. The hue magenta is the complement of green: magenta pigments absorb green light, thus magenta and green are opposite colors. Before "printer's magenta" was invented in the 1890s for CMYK printing, and "electric magenta" was invented in the 1980s for computer displays, these two artificially engineered colors were preceded by the color displayed at right, which is the color originally called "magenta" made from coal tar dyes in the year 1859. Besides being called original magenta, magenta dye