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

Charge transfer when oxygen gives its electron to Mn (7+) changing in Mn (6+) temporaily

Charge transfer when Mn (7 +) gives its electron to oxygen and oxidise to Mn (8+) temporaily

Oxygen gives colour to it

none is correct explanation