The Generalized Phase Contrast (GPC) method enables virtually loss free conversion of spatial phase patterns to highly efficient light intensity distributions. The GPC-method has been used in a number of applications requiring parallel light-beam encoding such as in advanced user-controlled optical micro-manipulation, wavefront sensing and generation for common-path interferometry and adaptive optics, optical phase-only encryption and integrated micro-optical implementations. In this work, we will outline the concept for a GPC-platform for advanced and user-interactive manipulation of fluid-borne colloidal structures with state-of-the-art controllability and versatility. Real-time reconfigurable light patterns with sub-micron accuracy are obtained from a direct map of phase patterns addressed on a programmable phase-only spatial light modulator device. A graphical user interface enables real-time, interactive and arbitrary control over the dynamics and geometry of synthesized light patterns. Arrays of GPC-generated counterpropagating light fields provides for multi-particle trapping and manipulation in three dimensions by incorporating a spatially-addressable polarization modulator where individual relative strengths of orthogonally-polarized beam-pairs are independently adjustable. The result is a system with fully independent control of a plurality of particles throughout all spatial dimensions and in real time, hence 4D optical multi-beam manipulation.