Oxygenic photogranules are photosynthetic aggregates of several millimeters in size, composed of heterotrophic bacteria living in syntrophy with photosynthetic cyanobacteria. This association of microorganisms can consume organic matter without external aeration, the cyanobacteria providing the oxygen needed by the heterotrophs for oxidizing the organic matter. Cyanobacteria are the key partner in this association since it provides the oxygen but also the physical structure for the outer layer of the photogranules. In bioreactors, photogranules are regularly exposed to variations of light intensities and cyanobacterial cells are receiving different quality of light depending on its position inside the photogranules. In order to study the physiological consequences of light variations, we developed several experimental devices to measure light penetration inside the photogranules and to be able to grow cyanobacteria under specific light colors. Seventeen cyanobacterial stains were isolated from photogranules and were grown in the standard BG11 medium. Several macroscopic morphotypes were observed in monoclonal culture, ranging from microbial mat, biofilm on air-liquid interface, flocs and granules. We investigated the ability of the different morphotypes to adapt their content in photosynthetic pigments (chlorophyll and phycocyanin). The strains were grown with the same light intensity (Photosynthetic Active Radiation (PAR) of 30 µE) under white, blue, green, orange and red lights. Differences in pigmentation were estimated by absorbance (ranging from 350 nm to 750 nm). Results will be discussed in the context of an environmental biorefinery, where photogranules can convert a low-grave organic feedstock into valuable by-products.