Magenta is a color that has as a deep, purplish-red hue that is one of the subtractive primary colors, complementary to the color green. A dye bearing the color was discovered in 1859, and it was called fuschine. The color was later renamed magenta after the Battle of Magenta, which took place in the same year the dye was discovered.
In the RGB and CMYK color models, magenta is located at the halfway point between red and violet. The odd thing about magenta is that, unlike other complementary colors, it does not exist in the visible spectrum. This is because it cannot be generated as a wavelength of light and therefore, should not exist.
The spectrum of light is made up of different wavelengths of electromagnetic radiation. Red generates the longest wavelength while violet has the shortest wavelength. The brain interprets the different wavelengths into colors as the light emitted by any object enters the eye.
The issue lies when the wavelengths from both ends of the spectrum representing red and violet are mixed. When these two wavelengths are summed up, the resulting color should be green, which will not make sense as a mixture of red and violet. The brain compensates for this by closing the color spectrum into a loop by inventing the color magenta.