The present invention discloses the use of functionalized particles as electrophoretic displaying particles, wherein the functionalized particles are SiO2, Al2O3 or mixed SiO2 and Al2O3 particles comprising, covalently bound to an oxygen atom on the surface, a radical of formula (1), wherein R1 and R2 are independently of each other hydrogen, particle surface-O—, or a substituent, n is 1, 2, 3, 4, 5, 6, 7 or 8, B is the direct bond or a bridge member, and D is the residue of an organic chromophore.