Embedding photonic crystals (PCs) into polymer matrix and direct promoting the interactions between building blocks through various forces (such as coordination bonds) are effective strategies for fabricating robust PC films. However, due to the adverse effect of metal salts on electrostatic repulsion during an assembly process, coordination bonds have long been ignored as an effective force for strengthening PC films. Herein, monodisperse PS@PEA-PAA core-shell spheres were prepared through a stepwise emulsion polymerization process and further formed complex with ZnCl₂ to serve as precursor for PC films. Under vertical compression at elevated temperatures, polymer shell melt drove PS cores towards assembly into highly ordered arrays with steric repulsion as the necessary balancing force and locked the whole structure. With 1 mL of AA monomer added for PS@PEA-PAA building blocks and 2 mmol of ZnCl₂ added to form complex precursor, compared with the results of PS@PEA PC films, coordination bonds in PS@PEA-PAA composite PC films induce 420.8% increase for Young’s modulus, which clearly demonstrates the impressive ability of coordination bonds for promoting mechanical properties. Blue, green and red PC films were prepared as the basic elements using 225 nm, 265 nm and 310 nm PS@PEA-PAA spheres as building blocks, respectively, which can be further combined selectively into cyan, violet and yellow PC films following the additive color mixing rule. The robust free-stranding PC films can be further tailored and recombined into PC patterns with versatile designing styles and abundant optional structural colors, demonstrating great value for practical applications.