Atomic and molecular glasses are more and more used for a variety of pur- poses nowadays, yet the e_ect of structural changes of glasses under an applied tension on the thermal equilibration process is not well-understood. To get a better understanding of what happens when a glass is suddenly deformed with a small strain, we use a colloidal glass to visualize its local mechanical responses in the elastic regime. We _rst assume that colloidal glass follows a_ne elas- tic deformations: we use two experimental colloidal con_gurations of crystal and glass and arti_cially shear the systems. We obtain a parabolic behavior of strain-free energy curves of these two con_gurations. We next shear our system in two di_erent ways to investigate the reversible transformations of colloidal glasses. In the _rst scenario, we shear our system from an unstrained state to a small strain and then unstrain the system. This procedure is repeated up to 3% strain. In the second case, we strain our system continuously up to 10% strain without removing the strain. In both cases we do not observe a_ne elastic behavior of the colloidal glasses but for the former case, we observe a reversible behavior of the shear transformation zones and free energy calculation in the system. In the later case, the shear transformation zones grow continuously with the applied strain of the system, and interestingly, the total free energy of the system declines parabolically with the increase of the strains. Our results con_rm that colloidal glasses perform non-a_ne behavior and highlight the role of the local shear transformation zone to activate the equilibration process of colloidal glasses in the elastic regime.