Quantitative parameters for behavior of homologous hemicyanine dyes in micellar media were determined using ultraviolet and visible differential spectroscopic technique. The impact of varying dye hydrophobicity on aggregation of surfactant was related to the extent of depression in critical micelle concentration of sodium docecyl sulfate caused by the addition of each dye. Spectral shifts were translated in terms of binding constants to highlight the involvement of dye molecules in the formation of surfactant-dye aggregates. Both spectroscopic and conductometric data were used to show the thermodynamic feasibility of the phenomenon.