A common problem for all color displays, regardless of whether they are of the self-luminous or non-self-luminous type, is the synthesis of a full-color image from a limited set of primary colors. Several approaches to color synthesis have been employed for electronic displays. The most successful of these conform to the principles of additive color mixture and include optical superposition, spatial synthesis and temporal synthesis. In order to understand the principles of color generation in electronic display systems, as well as the relative strengths and weaknesses of synthesizing color in the space and time domains, I first consider the visual bases which allow such color synthesis to occur. Although basic approaches to color synthesis have served the evolution of display technology well up to recent times, I present the argument that the continued evolution of display technology toward higher display resolution and enhanced color quality has exposed the limitations of both spatial color synthesis and temporal color synthesis and raises questions as to whether either method for synthesizing color can alone fully satisfy the ever increasing demands on display image quality. Clearly, new approaches to color synthesis are needed to sustain the evolution of display technology, and I describe recent concepts with the potential for pushing the horizons of color display image quality and reducing the costs of future color displays. These include hybrid spatial-temporal color synthesis and 3D color synthesis as well as variants of these approaches.