Apparatus comprising an electrowetting element with a first fluid and a second fluid immiscible with the first fluid. A support plate has a surface with a first surface portion lying in a first plane and overlapping a first electrode, and a second surface portion lying in a second plane different from the first plane. On receiving display effect data indicative of a requested display effect, the electrowetting element is switched to a state in which the first fluid contacts substantially all of the first surface portion and the second fluid contacts substantially all of the second surface portion, using a voltage with a voltage value which is within a range of a plurality of voltage values at which the electrowetting element is in the state.