The low-temperature photoluminescence (T<300 K) and UV-induced formation of color centers of recently synthesized Sr₂Bi₂O₅, Sr₃Bi₂O₆ and Sr₆Bi₂O₁₁ bismuthates are examined. The estimated Mott-Seitz activation energies, ranging from 88 to 167 meV, correspond to various emission bands. Comparison of the response of all three bismuthates when exposed to UV-illumination indicates that photoluminescence and formation of color centers are two processes that compete with photocatalytic activity. The most photoactive Sr₆Bi₂O₁₁ bismuthate exhibits neither luminescence nor the ability toward photocoloration. By contrast, Sr₂Bi₂O₅, which exhibits no photocatalytic activity, displays an intense photoluminescence; UV irradiation causes significant changes of its color. The bismuthate Sr₃Bi₂O₆ occupies an intermediate position as it exhibits some photocatalytic activity, as well as the ability to photoluminesce and to undergo photocoloration. Simple models are described to systematize the experimental results, which place these bismuthates into a new class of photoactive materials.