Spectral absorbance of chromium (III) chloride–alkali halide-water system was studied by dye indicator i.e. methyl orange. The absorbance of a series of mixed dye, chromium (III) chloride and alkali halides solutions has been measured. Here the dye concentration and one of salt concentration was kept constant and concentration of other salt was gradually increased. The absorbance at λmax against the other salt concentration shows eight peaks corresponding to complex ion formation between the salts in the ratio 6:1, 4:1, 3:1, 2:1, 3:2, 1:1, 2:3, 1:2. This can be explained on the basis of Frank-Condon principle.