Ink jet inks and liquid developers are disclosed which contain colored particles comprising hydrophilic silica particles, to the surfaces of which dyes are covalently bonded through silane coupling agents. The ink jet inks generally comprise a liquid medium and a plurality of the colored silica particles. The liquid developers generally comprise a liquid medium, a resin, a plurality of the colored silica particles, and a charge control agent. The particles are prepared by a process which comprises reacting hydrophilic silica particles with a silane coupling agent in the absence of water to form particles having covalently attached thereto coupling agents, followed by reacting a dye with the coupling agent attached to the silica particles.