The current designs of color video projectors suffer from color errors commonly referred to as rainbow artifact. This book contains a new projector hardware and processing technique that reduces the artifacts significantly. Our contributions are in three parts. We first propose the notion of rendering error, or an error in the projected image perceived by the human visual system. We then propose spatial-temporal color wheel design incorporated the requirements for the zero rendering error condition and amplitude demodulation. The output was satisfactory, although it required a modfied color wheel. Finally, we propose preprocessing scheme that reduce rendering error by introducing a correction term to cancel the predicted rendering error.