Magenta is a purplish red color evoked by lights with less power in yellowish-green wavelengths than in blue and red wavelengths (complements of magenta have wavelength 500–530 nm). In light experiments, magenta can be produced by removing the lime-green wavelengths from white light. It is an extra-spectral color, meaning it cannot be generated by a single wavelength of light, being a mixture of red and blue wavelengths. The name magenta comes from the dye magenta, commonly called fuchsine, discovered shortly after the 1859 Battle of Magenta near Magenta, Italy.

In the Munsell color system, magenta is called red-purple. In the CMYK color model used in printing, it is one of the primary colors of ink. In the RGB color model, the secondary color created by mixing the red and blue primaries is called magenta or fuchsia, though this color differs in hue from printer's magenta.

Magenta dye (1860)

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 fuchsine made from coal tar dyes in the year 1859. The name of the color was soon changed to magenta, being named after the Battle of Magenta near Magenta, Italy.

Process magenta (pigment magenta; printer's magenta) (1890s)

In color printing, the color called process magenta, or pigment magenta, or printer's magenta is one of the three primary pigment colors which, along with yellow and cyan, constitute the three subtractive primary colors of pigment. (The secondary colors of pigment are blue, green, and red.) As such, the hue magenta, is the complement of green: magenta pigments absorb green light; thus magenta and green are opposite colors.

The CMYK printing process was invented in the 1890s, when newspapers began to publish color comic strips.

Process magenta 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 magenta ink. A typical formulation of process magenta 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 the following website offering tintbooks for CMYK printing: 1. A printer's magenta is usually out of gamut on a computer display, so the color at right is only an approximation.

In Prismacolor colored pencils, this color (Prismacolor PC 994) is called process red (it would have been more accurate to call it process magenta). The Prismacolor colored pencil process red color is not quite as saturated as the color process magenta shown above.