A large number of experimental data on the viscous and the diffusive behavior at short and long times in three classes of disordered hard-sphere-like colloidal suspensions with varying polydispersity is compared with theory. At low and intermediate concentrations (volume fraction φ<0.35) a hydrodynamic description obtains. An alternative molecular approach, which can be generalized to high concentrations, is also presented. At high concentrations (φ>0.35) the...</0.35)>