A color-tunable plasmonic device is provided with a partially modulated refractive index. A first dielectric layer overlies a bottom electrode, and has a refractive index non-responsive to an electric field. A second dielectric layer overlies the first dielectric layer, having a refractive index responsive to an electric field. An electrically conductive top electrode overlies the second dielectric layer. A plasmonic layer including a plurality of discrete plasmonic particles is interposed between the top and bottom electrodes. In one aspect, the plasmonic layer is interposed between the first and second dielectric layers. In a second aspect, the plasmonic layer is interposed between the first dielectric layer and the bottom electrode. In a third aspect, a first plasmonic layer is interposed between the first dielectric layer and the bottom electrode, and a second plasmonic layer of discrete plasmonic particles is interposed between the first dielectric layer and the second dielectric layer.