An electrostatic printer comprising: a photoconductor member ; an imaging unit configured to generate a latent electrostatic image on the photoconductor member ; an interface configured to receive a developer unit comprising a colored toner, the developer unit configured to develop a colored toner image on the photoconductor member using an associated base developer voltage; and a controller , wherein the electrostatic printer is characterised in that the controller is configured to: obtain image data comprising first color separation data representing the colored toner and second color separation data representing a variant color of the colored toner having a different color density; control the imaging unit to generate on the photoconductor member a latent electrostatic image corresponding to the first color separation; control the developer unit to develop, using a base developer voltage, a toner image on the photoconductor member ; control the imaging unit to generate, on the photoconductor member , a latent electrostatic image corresponding to the second color separation; and control the developer unit to develop, using a variant developer voltage, a toner image on the photoconductor member , wherein the variant developer voltage is different to the base developer voltage. a photoconductor member ; an imaging unit configured to generate a latent electrostatic image on the photoconductor member ; an interface configured to receive a developer unit comprising a colored toner, the developer unit configured to develop a colored toner image on the photoconductor member using an associated base developer voltage; and a controller , wherein the electrostatic printer is characterised in that the controller is configured to: obtain image data comprising first color separation data representing the colored toner and second color separation data representing a variant color of the colored toner having a different color density; control the imaging unit to generate on the photoconductor member a latent electrostatic image corresponding to the first color separation; control the developer unit to develop, using a base developer voltage, a toner image on the photoconductor member ; control the imaging unit to generate, on the photoconductor member , a latent electrostatic image corresponding to the second color separation; and control the developer unit to develop, using a variant developer voltage, a toner image on the photoconductor member , wherein the variant developer voltage is different to the base developer voltage. obtain image data comprising first color separation data representing the colored toner and second color separation data representing a variant color of the colored toner having a different color density; control the imaging unit to generate on the photoconductor member a latent electrostatic image corresponding to the first color separation; control the developer unit to develop, using a base developer voltage, a toner image on the photoconductor member ; control the imaging unit to generate, on the photoconductor member , a latent electrostatic image corresponding to the second color separation; and control the developer unit to develop, using a variant developer voltage, a toner image on the photoconductor member , wherein the variant developer voltage is different to the base developer voltage. <EOS>