We report on the experimental attempts to apply mixed brushes for the reversible in situ switching colloidal systems (suspensions of smart nanoparticles in individual solvents and immiscible liquids). We used responsive polymer brushes to fabricate smart nanoparticles and employed the smart particles to prepare responsive colloids, which demonstrated drastic transformation/switching of material properties upon external stimuli.The interaction between the particles themselves and the particles and their environment can be precisely tuned by a change of solvent and pH. We show that this behavior can be used for a reversible formation of particle aggregates, stabilization and switching between w/o and o/w emulsions, and fabrication of smart coatings with textured surfaces.