A fast and highly controllable method of fabricating large films of photonic crystals of colloids is reported. A charge-stabilized colloidal suspension was run in a flat capillary driven by a pressure-regulated air pulse. The colloidal crystal texture formed in the capillary was a sensitive function of air pressure. Above a critical pressure, the entire capillary was filled with a uniform single-domain texture whose transmittance spectrum showed a high quality as a photonic crystal, i.e., excellent opacity at a photonic bandgap and high transparency at other wavelengths. The present method is easily applicable to industrial processes for mass production.