We first developed two ML models based on the photophysical properties of a styrenic polymer library synthesized from a naphthalene diimide (NDI)-based single-fluorophore initiator. Directed by the implications of the predicted results for de novo chemical design, we obtained a series of structurally simple, NDI-initiated TSCT polymers with various polycyclic aromatic donor groups. By varying the donor structure and loading amount, full-color tunable emission with continuous shifted wavelength or FRET-like bimodal spectra can be easily achieved. The experimental results robustly validated the predictions from the ML models. Time-dependent density functional theory (TD-DFT)-based calculations were performed to elucidate the TSCT ground-and excited-state energies and quantify the optimal donor-acceptor distance. We further showed that this universal polymer platform can be used to develop stimuli-responsive materials with high-contrast photochromic fluorescence for information encryption.