Color‐tunable smart afterglow materials in response to excitation wavelength and time simultaneously is highly important for anticounterfeiting and data encryption application, which remains a great challenge to date. Here, we provide a simple and efficient approach to develop color‐tunable afterglow supramolecular assembly AxBy@Lap in response to excitation wavelength and time simultaneously through the co‐assembly of non‐emissive nanoclay (Lap) and two different kinds of guests (A: Terephthalic acid (TPA), B: Terpyridine‐derivatives) using a simple solventless grinding method. Experimental and theoretical researches clear that the different decay lifetimes and origin for multiple afterglow emission centers bring about the aforementioned distinctive excitation wavelength‐ and time‐dependent feature. Furthermore, AxBy@Lap reveal excellent color‐tunable afterglow behavior with excitation wavelength‐ and time‐dependent feature in aqueous solution with water content of 99 wt %. Benefiting from this excellent characteristics, multi‐modal anti‐counterfeiting and encryption application were exhibited. [ABSTRACT FROM AUTHOR]