According to the characteristics of discrete cosine transform spectrum images and the characteristics of contrast sensitivity of human vision system to brightness and color, a method was proposed to calculate a minimum error of human eye perceiving images which was JND threshold namely. By calculating the JND threshold, a color image watermark technology program was proposed based on YC-rC-b color space. According to JND threshold, matrix coefficients of the spectrum images of three components brightness images of color image were filtered to carry out embedding and extracting watermark. From watermarking technology program, JND threshold made the watermark embedded into the maximum. Embedded watermark algorithm made the position embedded watermark random, which effectively ensured the security of watermark information. Simulation experiments and attacks tests result showed that the compressed images which were embedded watermark were basically the same with the original image; the extracted watermark is basically the same with original watermark information; the images embedded watermark after attack has good transparency and high robustness. It was concluded that the proposed color image watermark scheme based on YC-rC-b color space and human visual system characteristics is a feasible and better color imaging technology.