An apparatus for developing a latent image recorded on an imaging surface (10) with a custom color toner, including a developer housing (100) for developing a portion of said latent image with the toner of custom color. The developer housing (100) includes a donor member (42) for transporting toner of the custom color to a development zone (C) to develop the latent image. A replaceable reservoir unit (60) is provided for mixing and supplying the custom color toner to the donor member (42). An array of toner dispensers (66) is provided for supplying various primary color toners, as required, to achieve the custom color, and additional reservoirs (60) having various colored toners therein to allow for faster convergence to a given point in the color space.