The interaction of dye and surfactants was studied by their spectroscopic and surface properties. Large bathochromic shift (15 nm) in the absorption spectrum was found for aminoindophenol dye at high pH in cationic surfactant, while there is no significant shift in anionic, zwitterionic and nonionic surfactant solutions. The static and dynamic surface properties show there is strong interaction in mixture of cationic surfactant and aminoindophenol dye. Interaction of dye and surfactants on surface and in solution is correlated to the intensity of dye deposition on fiber. The charge complex formation between cationic surfactant and aminoindophenolic dye delays the dye diffusion into keratin fiber. The stronger is the dye/surfactant interaction, the lower dye deposition and diffusion become. (C) 2004 Elsevier Inc. All rights reserved.