${\mathrm{MnO}}_4^{-}$ is of intense pink colour, though Mn is in ( +7) oxidation state, it is due to :

The color in ${\mathrm{MnO}}_4^{-}$ arises from an electronic transition, but it is actually not a d-d transition, since the Mn in this compound has no d electrons. It arises from a charge transfer reaction within the molecule, in which photons promote an electron from the highest energy molecular orbital in one of the Mn-O bonds to an empty d orbital on the manganese. This promotion is equivalent to the energy of a yellow photon, so yellow light is absorbed leaving us to see purple, the complementary color.