The permittivities of ceramic-based colloidal suspensions in electric fields were measured under steady and oscillatory shearing flows. Under steady shear flow, a unique relationship defined the dependence of permittivity on viscosity for suspensions of differing volume fractions under various applied fields. Under oscillatory shear flow, the maximum in permittivity coincided with the minimum strain under high fields and low strain amplitudes but coincided with the minimum strain rate under low fields and high strain amplitudes.