In this paper, a semi-blind watermarking technique of embedding the color watermark using curvelet coefficient in RGB cover image has been proposed. The technique used the concept of HVS that the human eyes are not much sensitive to blue color. So the blue color plane of the cover image is used as embedding domain. A bit planes method is also used, the most significant bit (MSB) plane of watermark image is used as embedding information. Selected scale and orientation of the curvelet coefficients of the blue channel in the cover image has been used for embedding the watermark information. All other 0-7 bit planes are used as a key at the time of extraction. The results of the watermarking scheme have been analyzed by different quality assessment metric such as PSNR, Correlation Coefficient (CC) and Mean Structure Similarity Index Measure (MSSIM). The experimental results show that the proposed technique gives the good invisibility of watermark, quality of extracted watermark an