The effect of photoinduced reversible coloration was discovered and investigated in superionic RbAg4I5 crystals exposed to light irradiation 2.92 eV less than or equal to h nu less than or equal to E(g) = 3.2 eV at T = 300 K. Spectral efficiency measurements of the photoinduced effect let to the discovery that profound changes in the absorption spectrum of RbAg4I5 crystals are observed on 2.92 eV light irradiation. Relaxation of the photoinduced absorption after cessation of the irradiation was found to be of exponential form with a time constant of about 900 s. The mechanism of the photoinduced coloration is considered to be due to self-trapped holes injection under the irradiation of RbAg4I5 superionic crystals.