In this work the authors compare different approaches for implementing color space converters (from RGB to YCbCr and back) using constant matrix multiplication. The results are optimized low-complexity realizations suitable for high-speed and low-power implementation in ASICs or FPGAs. It is also shown that the power varies significantly even if the number of additions required is the same. Furthermore, the authors show that compared with previously available FPGA implementation the proposed ones are advantageous