This paper describes the hardware architecture and the employed algorithm of a parallel processor system for three-dimensional color graphics. The design goal of the system is to generate realistic images of three-dimensional environments on a raster-scan video display in real-time. In order to achieve this goal, the system is constructed as a two-level hierarchical multi-processor system which is particularly suited to incorporate scan-line algorithm for hidden surface elimination. The system consists of several Scan-Line Processors (SLPs), each of which controls several slave PiXel Processors (PXPs). The SLP prepares the specific data structure relevant to each scan line, while the PXP manipulates every pixel data in its own territory. Internal hardware structures of the SLP and the PXP are quite different, being designed for their dedicated tasks.