This study focused on watermarking algorithm for security targeting at the piracy approach of printing and scanning. According to the character of resisting geometrical transformations of singular value discrete (SVD) and multi-resolution transform of discrete wavelet transform (DWT), a watermark algorithm was proposed which based on CIE1976L*a*b* color space. And through the simulation experiment, the efficiency of the algorithm was evaluated. The E value between the watermarked color image and the original image was 1.2183, which was less than 3. And at least one of the watermarks which were extracted from the image was effective, the R value was larger than 0.6. The algorithm can insure the watermark to be invisible and is robust against common printing and scanning process or image processing operations.