Colorant selection and optimization is an important issue for high-fidelity color reproduction. A new colorant selection algorithm for high-fidelity color reproduction was put forward to offset the maximum color gamut gap between display and print. Our study showed that the maximum gamut gaps of red, green, and blue between display and print lie in the middle tone of red, bright tone of green and dark tone of blue. Light red and light green was proposed, in addition to traditional CMYK, as the new six primary colorants. The light red and light green ink were selected, the gamut were simulated by computer. Results showed that the new six primary colorants we proposed can extend the printing gamut efficiently.