A composition and method for encapsulating colorant molecules in polymeric particles are described. Colorant molecules, such as dye, are doped or embedded in a particle, at least in part, composed of a halogen-containing polymeric matrix that can effectively isolate the dye molecules from reaction with photo-oxidizing or reducing agents. The isolated colorant molecule is protected from photo-bleaching and other color degradation, and show superior photo-stability. The encapsulating polymer matrix can be cross-linked and can have a variety of surface functional groups, which may be adapted to help achieve either strong ionic or covalent binding to desired substrates. Also described are methods for producing protective particles, and ink mediums for applying the particles to substrates.