A switchable reflective colour filter is provided for use in a display device. The switchable reflective colour filter includes a plurality of sub-pixel regions of at least two colour types, each including a layer of phase change material which is switchable between a first state and a second state, the first and second states being two solid but structurally distinct states having different optical properties. Each sub-pixel region further includes two electrode layers, a mirror layer, and a spacer layer or air gap. The phase change material layer in each sub-pixel region is positioned between the two electrode layers, and separated from the mirror layer by the spacer layer or air gap. The switchable reflective colour filter may be incorporated into a display device including a pixelated switchable absorber. A luminance of coloured light reflected from any of the sub-pixel regions is controllably attenuated