A display (10, 24, 40) comprising: a transmission-type spatial light modulator panel having addressable pixels; a plurality of narrow-band light-emitting elements (21A, 21B, 21C) arranged to illuminate the panel with narrow-band light of a plurality of colors, respectively; wherein the narrow-band light of a particular color is monochromatic light; and at least one broadband light source arranged to illuminate the panel with broadband light having a broadband spectral power distribution; wherein the broadband light includes any of white light, blue-green light, yellow light and magenta light or mixtures thereof, wherein the broadband light has a spectral bandwidth at half maximum of at least 150 nm; wherein the broadband light source is controllable to alter an amount of the broadband light illuminating an area on the panel; wherein an area comprises a pixel or a group of pixels; wherein the panel is configured to reproduce a first gamut of colors if illuminated only by light from the broadband light source; wherein a size of the first gamut is a function of luminance; wherein the panel is configured to reproduce a second gamut of colors if illuminated only by light from the plurality of narrow-band light-emitting elements (21A, 21B, 21C); wherein the first gamut is entirely contained within the second gamut; a controller connected to receive image data and configured to determine from the image data a chromaticity and luminance corresponding to the area on the panel; and, based at least in part on the chromaticity, control the amount of the broadband light at the area on the panel; wherein the controller is configured to determine whether the chromaticity falls within a first chroma region lying within the first gamut and, if so, perform illumination of the area on the panel with the broadband light only; wherein the controller is configured to determine whether the chromaticity falls within a second chroma region lying within the second gamut but falls outside the first chroma region and, if so, perform illumination of the area on the panel with the narrow-band light from at least one of the plurality of narrow-band light-emitting elements (21A, 21B, 21C) and with the broadband light; and wherein the controller is configured to determine whether the chromaticity falls outside the second chroma region and, if so, perform illumination of the area on the panel with the narrow-band light from at least one of the plurality of narrow-band light-emitting elements (21A, 21B, 21C) only. a transmission-type spatial light modulator panel having addressable pixels; a plurality of narrow-band light-emitting elements (21A, 21B, 21C) arranged to illuminate the panel with narrow-band light of a plurality of colors, respectively; wherein the narrow-band light of a particular color is monochromatic light; and at least one broadband light source arranged to illuminate the panel with broadband light having a broadband spectral power distribution; wherein the broadband light includes any of white light, blue-green light, yellow light and magenta light or mixtures thereof, wherein the broadband light has a spectral bandwidth at half maximum of at least 150 nm; wherein the broadband light source is controllable to alter an amount of the broadband light illuminating an area on the panel; wherein an area comprises a pixel or a group of pixels; wherein the panel is configured to reproduce a first gamut of colors if illuminated only by light from the broadband light source; wherein a size of the first gamut is a function of luminance; wherein the panel is configured to reproduce a second gamut of colors if illuminated only by light from the plurality of narrow-band light-emitting elements (21A, 21B, 21C); wherein the first gamut is entirely contained within the second gamut; a controller connected to receive image data and configured to determine from the image data a chromaticity and luminance corresponding to the area on the panel; and, based at least in part on the chromaticity, control the amount of the broadband light at the area on the panel; wherein the controller is configured to determine whether the chromaticity falls within a first chroma region lying within the first gamut and, if so, perform illumination of the area on the panel with the broadband light only; wherein the controller is configured to determine whether the chromaticity falls within a second chroma region lying within the second gamut but falls outside the first chroma region and, if so, perform illumination of the area on the panel with the narrow-band light from at least one of the plurality of narrow-band light-emitting elements (21A, 21B, 21C) and with the broadband light; and wherein the controller is configured to determine whether the chromaticity falls outside the second chroma region and, if so, perform illumination of the area on the panel with the narrow-band light from at least one of the plurality of narrow-band light-emitting elements (21A, 21B, 21C) only.