pH-responsive photonic block copolymer (BCP) colloids typically exhibit optical changes through uniform and reversible swelling–deswelling of internal domains, which lacks pathway dependence and stimulus memory. Here, we demonstrate that controlled partial quaternization of PS-b-P2VP colloids using 1,10-dibromodecane pre-encodes internal morphological heterogeneity, which fundamentally alters the pH-response pathway. Upon acidic exposure, this heterogeneity gives rise to hydration-driven swelling gradients, leading to time-dependent chain reorganization and topological reconstruction of internal domains. This heterogeneity-driven reconstruction produces a progressive blue-shift of structural color, reflecting an irreversible, history-dependent photonic response. This work establishes a design principle for programming non-equilibrium optical behavior in BCP colloids, enabling functional materials that encode environmental exposure into persistent structural and optical states.