The effect of several polyelectrolytes on the absorption spectrum of crystal violet (CV) has been studied over a wide range of pH. The following polymers were used: isotactic poly(methacrylic acid), PMAi; conventional poly(methacrylic acid), PMAc; a methacrylic acid (80%)-styrene (20%) copolymer, PMAS; and poly(styrene sulfonic acid), PSSA. Distinctly different effects were observed in the four cases. This has been interpreted in terms of a dependence of the degree and mode of binding of cationic dye molecules onto the polyacids on the hydrophobicity of the macroions.