While conventional synthetic plasmonic colloids have been well known, biogenic plasmonic biocolloids have to be introduced and demonstrated here as a new class of functional material that promise a wider field of applications in modern technology. Here, we introduce the "Bioshell" concept as an approach to biogenically fabricate plasmonic biocolloids whose unique colors are tuneable depending on their surrounding shellosome. The plasmonic biocolloid is an 'active compound' containing nanoparticles that can interact "actively" with biomolecules and modify their function and conformational dynamic. Interestingly, the smart and active performance of such biocolloids, done via conformational dynamic of its biological component, can be resembled to that of various natural materials. Inspired from Nature and creatures such as Zebra mussel, here, for the first time, we devise a plasmonic bioadhesive colloid that can perform underwater.