Permanent Magenta is from the family of aniline dyes which were derived originally from natural vegetable indigo. An international race was on in the 1800’s to determine the potential of synthetic colors. It was eventually discovered that several colors had the same substance in common, so they were thereafter referred to as aniline dyes.The name Magenta honors the town where the Franco-Piedmontese army was victorious over the Austrians in 1859. Due to its expense, the aniline was reserved for the wealthy, but as demand from the public was finally met, Magenta actually fell from favor as it was no longer regarded as a status symbol.
In 1935 the family of quinacridone dyes were developed, and the intense violet-red pigment of Quinacridone Magenta was produced by Winsor & Newton in 1958. Quinacridone pigments are highly sought after in the industrial and automobile industries because they have high color intensity and lightfastness. For example, although modern formulations of Alizarin have been improved to a B or moderately permanent rating, Quinacridone Magenta has an A or permanent rating.
I copied this section verbatim from the color guide because it is truly amazing:
For a colour so renowned for its’ intensity, there is a surprising fact about Magenta: it is not on the light spectrum. So, if it isn’t there, how can we see it? The answer lies in how we see light. When our brain sees waves of light from two ends of the spectrum, red and violet, scientists have learned that our brain invents a new colour for us, halfway between the two colours. Magenta has no wavelength attributed to it, unlike all the other spectrum colours, because it is really a bridge between colour; it was invented by our minds to address a perceived gap. The light spectrum doesn’t need to fill every gap, but obviously, the human mind wants to make sense of colour, and a part of that process of making sense of colour created magenta.”Winsor&Newton Colour Stories