A plasmonic pixel structure, comprising: a substrate; a plurality of nano-scale structures each comprising conducting and dielectric components, whereby the nano-scale structures are configured to act as nano-antennas. The nano-scale structures 5 have resonant frequencies that depend on the conducting component and sizes of the nano-scale structures. The conducting component and the sizes of the nano-scale structures are selected according to a wavelength component or components of incident light desired to be reflected or transmitted by the nano-scale structures, and the conducting component and the sizes of the nano-scale structures are selected 10 such that the nano-scale structures have respective resonant frequencies corresponding to a colour scheme.