  Charged plasmas with chirality imbalance are unstable and tend to reduce the
imbalance. This chiral plasma instability is, however, not captured in
(anomalous) hydrodynamics for high-temperature non-Abelian plasmas. We derive a
Langevin-type classical effective theory with anomalous parity-violating
effects for non-Abelian plasmas that describes the chiral plasma instability at
the magnetic scale. We show that the time scale of the instability is of order
$[g^4 T \ln(1/g)]^{-1}$ at weak coupling.
