Comprehensive SummaryConsidering their oriented crystalline structure and high luminescent efficiency, the exploration of multi‐component organic cocrystal systems with tunable supramolecular nanostructures and potential RGB light emission has emerged as a captivating but challenging subject. Here, we propose a straightforward synthetic strategy to precisely govern the assembly, structure and structure‐property relationship of organic cocrystals. By employing the single‐crystalline template‐assisted epitaxial growth (SCT‐EG) method, the two‐dimensional (2D) highly‐aligned cocrystal nanomeshes are firstly developed to afford an exceptional RGB trichromatic system, triggering cross‐modulation white light emission (WLE) with remarkable stability and regeneration capacity over six months. The transformation from random 1D microstructures to uniformly‐oriented 2D nanomeshes can be attributed to the regulatory competitive intermolecular π‐π, CT interactions, and partial H bond interactions among cocrystals. Moreover, the successful construction of 2D RGB trichromatic cocrystal nanomeshes system holds promise to generate full‐color display, which can function as multicolor inks for photonic dynamic recognition, information encryption, and decryption.