A colour active matrix electroluminescent (EL) display device has an array of pixels (10) comprising sets of red, green and blue emitting pixels, each of which pixels comprises an EL display element (20), a drive transistor (22) for driving a current through the display element, a storage capacitor (24) for storing a voltage used for addressing the drive transistor, and a discharge photosensitive element (40, 42) for discharging the storage capacitor in dependence on the light output of the display element. The discharge photosensitive elements (42) in the set of blue pixels comprise lateral photosensitive thin film devices, such as lateral thin film transistors or gated or ungated lateral photodiode devices, while the discharge photosensitive elements (40) in the set of red pixels, and preferably the set of green pixels as well, comprise vertical p i n photodiodes (40). The selection of the photosensitive elements in this manner leads to enhanced colour-related photo-sensitivity, and thus improved display device performance.