Among the techniques used to detect for multiple proteins in solution, a bead-based immunoassay using hydrogel microparticle is one of the methods noted for its possibility to quantify multiple analytes with graphically encoded microparticle. However, it is still limited to practical use because protein-bound microparticles is labeled by fluorescent dye which has problem for fluorescence quenching and requires expensive equipment to analyse signal. Herein, we introduce colorimetric detection to bead-based assay using hydrogel microparticle. Using colour dyes generated in an amplifiable enzymatic reaction in the presence of a target proteins, which accumulate in pores of microparticle, particles are imaged and analysed using low-cost portable devices.