Electric field optically responsive nanowire (NW) colloids can be applied for low-cost electro-optical devices (i.e. smart windows, switches) [1], detectors and sensors [2], as well as dielectrophoretic self-assembly of NWs into macroscopic yarns [3]. Smart windows are commonly based on visible light absorbing small oblong nanoparticles where transmittance is modulated by aligning nanoparticles towards direction of electric field and thus changing light absorption cross-section [4, 5]. These devices require high nanoparticle concentrations up to 10 wt%. High concentration hinder oblong nanoparticles to re-align into chaotic state after electric field is switched off and re-alignment may take up to several hours [4, 5]. These devices also switching transmittance between fully non-transparent to approximately 50% transmittance at 550 nm [4, 5], which is not suitable range for practical applications.