We have succeeded in the simultaneous photoluminescence in the two colors, red and green, from a single nano-sized zeolite crystallite contg. Eu(III) and Tb(III) as exchanged cations in a cavity through photosensitization by an org. photosensitizer (benzophenone). Paths of energy transfer from Eu(III) ions to Tb(III) ions and from Tb(III) ions to Eu(III) ions have been revealed in addn. to the primary energy transfer from the excited triplet state of the photosensitizer to both cations.