Colloidal crystal heterostructures composed of two different material systems (organic polystyrene colloids and inorganic silica colloids) have been fabricated on horizontal solid substrates with an inward-growing self-assembly method. Microstructure characterization results showed high quality of the resultant colloidal crystal heterostructures. Optical measurements clearly demonstrated the presence of different stop bands as a consequence of the superposition of the stop bands from the individual compositional colloidal crystals. (c) 2005 Elsevier B.V. All rights reserved.