Methods of preparing electrophoretic dispersions containing two types of particles with different colors and opposite charges

A dielectric dispersion, comprising:

• (a) a dielectric fluid;
• (b) a first plurality of particles of a first color having a surface charge of a selected polarity dispersed within said dielectric fluid;
• and
• (c) a second plurality of particles of a second color which contrasts substantially with said first color, having a surface charge of opposite polarity to that of said first plurality of particles;
• and
• (d) means for preventing coagulation of said first and second plurality of particles, wherein said means includes a charge control agent for positively charging said first plurality of particles., a second charge control agent for negatively charging said second plurality of particles, and a stabilizer for thermodynamically stabilizing said first plurality of particles and said second plurality of particles, wherein said stabilizer is selected from the group consisting of homopolymers, copolymers, graft polymers, block polymers, and natural high molecular weight compounds.