A new method describing the in situ synthesis of azo dyes in the mesopores of acidic faujasites is presented, where the coupling component N,N-dimethylaniline is adsorbed by interaction with the acidic centers, and zinc double salts of diazo compounds are added in weak acidic solution. Ship-in-the-bottle synthesis is achieved for azo dyes where the largest dimension of one component, i.e., approximately 0.7 nm, becomes the smallest one of the complete chromophore. The azo coupling does not proceed in the supercages, presumably because of spatial constraints for the transition state of the process. The in situ synthesis enables the incorporation of unstable chromophores that decompose during the crystallization inclusion. Also, the synthesis of the zwitterionic methyl orange in the negatively charged faujasite was successful.