KMnO4 in aqueous solution is violet in color and is reduced to Mn2+ which does not color the solution.
MnO4- (aq) + 8 H+(aq) + 5 e- = Mn2+(aq) + 4H2O
KMnO4 is often the titrant and reacts with the titrand (analyte). At the equivalence point the solution takes on a violet/purple color.
If KMnO4 is the titrand, then the violet color disappears. However, if the KMnO4 concentration is high enough, MnO2 (brown precipitate) may be formed.
4MnO4- (aq) + 4H+ (aq) + 4e- = 4 MnO2 (s) + 3O2 (aq) + 2H2O(l)
An example of manganimetric color titration is described in the potassium permanganate index method.