When a color image is converted into a monochrome one, luminance components of the pixels have been used as gray-levels for the representation of the monochrome image in HDTV standard. However, saliencies of the image embedded only in the chrominance components are disappeared in the monochrome image converted by using luminance components. To cope with this problem, A.A. Gooch et al. have proposed the salience-preserving color removal method called "Color2Gray". The monochrome image well reflected the impression of an input color image can be yielded by Color2Gray. However, the calculation cost of that algorithm is tremendous, and its utility is not so much. In this paper, fast Color2Gray algorithms are proposed. The effectiveness of the proposed method is illustrated through the experiments.