An electrophoretic display has a viewing surface, and includes an image pixel. The image pixel includes a first plurality of particles having a first mobility, and a second plurality of particles having a second mobility. At a first addressing voltage, the first mobility is greater than the second mobility. At a second addressing voltage, the second mobility is greater than the first mobility. At least one of the first and second mobilities is a variable function of voltage, i.e., a function of an applied electric field. Application of the first addressing voltage produces a first optical state, which is determined by a motion of the first plurality of particles. Application of the second addressing voltage produces a second optical state determined by a motion of the second plurality of particles.