An electrophoretic display medium includes at least one set of colored particles in a dielectric fluid, wherein the dielectric fluid is a silicone fluid, and wherein the display medium has an electrical conductivity of about 10−11 to about 10−15 S/m. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.