The work is devoted to investigation of stable coloration induced by gamma radiation from 60 Co (1.25 MeV) in pure and neodymium doped Ca0.28Ba0.72Nb2O6 single crystals. Nature of the induced absorption is discussed. This absorption is due to charge change of native defects or ions forming of crystals (vacancy, niobium ions, etc.). The nature of color centers responsible for induced absorption is discussed.