An electrowetting display device comprising: a greyscale picture element layer comprising a plurality of first picture elements, each first picture element of the plurality of first picture elements having a respective first fluid configurable to provide a greyscale display state; a colour picture element layer comprising a plurality of second picture elements, each second picture element of the plurality of second picture elements having a respective second fluid configurable to provide a colour display state, each first picture element of the plurality of first picture elements and each second picture element of the plurality of second picture elements having a respective display area for providing a display effect thereover, wherein each first picture element of the plurality of first picture elements has a respective lateral extent which aligns with a lateral extent of three second picture elements of the plurality of second picture elements, each first picture element of the plurality of first picture elements being arranged on an optical axis in common with a second picture element of the plurality of second picture elements; and a control system arranged to change a configuration of the first fluid of each first picture element of the plurality of first picture elements and the second fluid of each second picture element of the plurality of second picture elements by changing a voltage applied to at least one first electrode associated with a respective first picture element of the plurality of first picture elements and at least one second electrode associated with a respective second picture element of the plurality of second picture elements, respectively, the control system also being arranged to switch the electrowetting display device between: a colour display mode where the first fluid does not substantially cover the respective display area of each first picture element of the plurality of first picture elements; and a greyscale display mode where the second fluid does not substantially cover the respective display area of each second picture element of the plurality of second picture elements. a greyscale picture element layer comprising a plurality of first picture elements, each first picture element of the plurality of first picture elements having a respective first fluid configurable to provide a greyscale display state; a colour picture element layer comprising a plurality of second picture elements, each second picture element of the plurality of second picture elements having a respective second fluid configurable to provide a colour display state, each first picture element of the plurality of first picture elements and each second picture element of the plurality of second picture elements having a respective display area for providing a display effect thereover, wherein each first picture element of the plurality of first picture elements has a respective lateral extent which aligns with a lateral extent of three second picture elements of the plurality of second picture elements, each first picture element of the plurality of first picture elements being arranged on an optical axis in common with a second picture element of the plurality of second picture elements; and a control system arranged to change a configuration of the first fluid of each first picture element of the plurality of first picture elements and the second fluid of each second picture element of the plurality of second picture elements by changing a voltage applied to at least one first electrode associated with a respective first picture element of the plurality of first picture elements and at least one second electrode associated with a respective second picture element of the plurality of second picture elements, respectively, the control system also being arranged to switch the electrowetting display device between: a colour display mode where the first fluid does not substantially cover the respective display area of each first picture element of the plurality of first picture elements; and a greyscale display mode where the second fluid does not substantially cover the respective display area of each second picture element of the plurality of second picture elements. a colour display mode where the first fluid does not substantially cover the respective display area of each first picture element of the plurality of first picture elements; and a greyscale display mode where the second fluid does not substantially cover the respective display area of each second picture element of the plurality of second picture elements.