Abstract: Composite hydrogels with a chiral organization with tunable responsive photonic properties are conceived. A polymerizable hydrophilic monomer such as acrylamide is reacted in the presence of nanocrystalline cellulose (NCC) to give a composite hydrogel with cellulose nanocrystals embedded in a chiral nematic organization. Through control of the reaction conditions, the hydrogel can exhibit photonic colour that can be varied throughout the visible and near-infrared regions. The colour shifts substantially and reversibly upon swelling and shrinking of the hydrogel through solvation in aqueous and nonaqueous media. The responsive properties can be tailored both through choice of monomer and/or through chemical modification of the NCC surface. Examples of possible applications of the materials are: tunable reflective filters, chemical sensors, stationary phases for electrophoresis of chiral or achiral substances, and as a template to generate new materials with chiral nematic structures.