Mauveine is a mixture of four related aromatic compounds differing in number and placement of methyl groups.  Its organic synthesis involves dissolving aniline, p-toluidine, and o-toluidine in sulfuric acid and water in a roughly 1:1:2 ratio, then adding potassium dichromate.
Mauveine A () incorporates 2 molecules of aniline, one of p-toluidine, and one of o-toluidine. Mauveine B () incorporates one molecule each of aniline, p-toluidine, and two of o-toluidine.  In 1879, Perkin showed mauveine B related to safranines by oxidative/reductive loss of the p-tolyl group.  In fact, safranine is a 2,8-dimethyl phenazinium salt, whereas the parasafranine produced by Perkin is presumed to be the 1,8- (or 2,9-) dimethyl isomer.
The molecular structure of mauveine proved difficult to determine, finally being identified in 1994.  In 2007, two more were isolated and identified: mauveine B2, an isomer of mauveine B with methyl on different aryl group, and mauveine C, which has one more p-methyl group than mauveine A.
In 2008, additional mauveines and pseudomauveines were discovered, bringing the total number of these compounds up to 12. In 2015 a crystal structure was reported for the first time.