Novel polyacrylamide hydrogels containing immobilized bilayer membranes have been synthesized and characterized. Iridescent color appears to result from the Bragg diffraction of visible light by the periodic structure of bilayer membranes of a polymerizable surfactant (n-dodecyl glyceryl itaconate (DGI). The iridescent structure of DGI has been immobilized inside a polyacrylamide gel. The iridescent color of the gel thus obtained can be changed by controlling the swelling degree of the gel. Anisotropic hydrogels in the entire bulk body have been synthesized by polymerizing the gels under shear flow and immobilizing the macroscopically aligned bilayer membranes inside the gel networks.