A pixelated optical filter (900, 1000, 2000, 3000, 4000, 5000, 6000, 7000) comprising: a Zero-Order Diffractive Filter, comprising: high-index refraction material (920, 1020, 4020) positioned between low-index-refraction matter (910, 930, 1010, 1030, 4010, 4030); wherein at least some of said high-index refraction material has a grated structure (925, 1025, 4025) and lateral and vertical dimensions with respect to said low-index-refraction matter such that said high-index refraction material is operative to act as a leaky waveguide for light incident on said pixelated optical filter; wherein said grated structure comprises a plurality of grating patterns that is planarly bounded; wherein each of said plurality of grating patterns constitutes a subpixel (950, 1500, 1510, 1520, 2500, 3500, 4500, 5500, 6500, 7500); wherein a plurality of said subpixels is defined by at least two neighbouring grating patterns (P1,P2) differing at least by their periods; wherein both grating patterns (P1,P2) have periods in the wavelength range between 200 nm and 650 nm; wherein optionally the grating profile, the depth and the orientations of each of said subpixels is different for each subpixel; wherein said plurality of subpixels is operative to diffract incident light to at least two zero-order wavelength spectrum respective of said at least two grating patterns, and wherein at least two of said subpixels exhibit a combined colour effect or wavelength spectrum, which cannot be generated by a single wavelength spectrum characterized in that the pixelated optical filter comprises a plurality of subpixels arranged in a matrix layout so that said pixelated optical filter renders a colour image. a Zero-Order Diffractive Filter, comprising: high-index refraction material (920, 1020, 4020) positioned between low-index-refraction matter (910, 930, 1010, 1030, 4010, 4030); wherein at least some of said high-index refraction material has a grated structure (925, 1025, 4025) and lateral and vertical dimensions with respect to said low-index-refraction matter such that said high-index refraction material is operative to act as a leaky waveguide for light incident on said pixelated optical filter; wherein said grated structure comprises a plurality of grating patterns that is planarly bounded; wherein each of said plurality of grating patterns constitutes a subpixel (950, 1500, 1510, 1520, 2500, 3500, 4500, 5500, 6500, 7500); wherein a plurality of said subpixels is defined by at least two neighbouring grating patterns (P1,P2) differing at least by their periods; wherein both grating patterns (P1,P2) have periods in the wavelength range between 200 nm and 650 nm; wherein optionally the grating profile, the depth and the orientations of each of said subpixels is different for each subpixel; wherein said plurality of subpixels is operative to diffract incident light to at least two zero-order wavelength spectrum respective of said at least two grating patterns, and wherein at least two of said subpixels exhibit a combined colour effect or wavelength spectrum, which cannot be generated by a single wavelength spectrum high-index refraction material (920, 1020, 4020) positioned between low-index-refraction matter (910, 930, 1010, 1030, 4010, 4030); wherein at least some of said high-index refraction material has a grated structure (925, 1025, 4025) and lateral and vertical dimensions with respect to said low-index-refraction matter such that said high-index refraction material is operative to act as a leaky waveguide for light incident on said pixelated optical filter; wherein said grated structure comprises a plurality of grating patterns that is planarly bounded; wherein each of said plurality of grating patterns constitutes a subpixel (950, 1500, 1510, 1520, 2500, 3500, 4500, 5500, 6500, 7500); wherein a plurality of said subpixels is defined by at least two neighbouring grating patterns (P1,P2) differing at least by their periods; wherein both grating patterns (P1,P2) have periods in the wavelength range between 200 nm and 650 nm; wherein optionally the grating profile, the depth and the orientations of each of said subpixels is different for each subpixel; wherein said plurality of subpixels is operative to diffract incident light to at least two zero-order wavelength spectrum respective of said at least two grating patterns, and wherein at least two of said subpixels exhibit a combined colour effect or wavelength spectrum, which cannot be generated by a single wavelength spectrum characterized in that the pixelated optical filter comprises a plurality of subpixels arranged in a matrix layout so that said pixelated optical filter renders a colour image.