Aqueous suspension droplets assume spherical shape on superhydrophobic substrates. We used such drying sessile droplets as templates for assembling latex microspheres and gold nanoparticles into closed packed structures due to restricted free volume. Spherical opals of 1- 2 mm in size could be easily produced within an hour in large quantities by this very simple and efficient process. Upon illumination with collimated light, the dried spherical supraparticles display discrete colored rings created by the periodic arrangement of latex particles in the surface layer. The physical origin of the colored patterns and the relationship between the size of colored rings generated by incident light and nanoparticle size were characterized. We found that ring size decreases as the latex particle diameter in the opals increases. This trend is quantified using Bragg's law of diffraction. Patterning of the substrates and controlled pinning of the droplet templates allows synthesizing nanoparticle assemblies of more complex shape and composition.