Abstract: The invention relates to a color matching method for transforming a color representation of a first set of color primaries with a plurality of first signals to a second set of color primaries with a plurality of second signals in a first domain. The color matching method of the invention is to consider the characteristics of human visual perception. Since human is more sensitive to the luminous intensity than chrominance, the color matching method of the invention is considered to match the luminous intensity. The color matching method of the invention can minimize the intensity difference by utilizing the optimality of resource distribution. An additional step of smoothing the intensity difference among color primaries at the level of color primaries is appended. It enhances the visual quality especially for the images with a gradual change in numerous levels of color. Besides, when the color is outside the gamut, we keep the information of luminance by adding extra white.