The most effective approach to achieving color consistency lies in accurate spectrum modeling, and the key to recover a faded spectrum is to recall the chromogenic metamer. In this paper, a spectral modeling mechanism is designed utilizing three primary colors as its core. Spectral recovering has been completed for all of the 1269 Munsell colors with corresponding RGB parameters. With both maximum entropy (ME) and least mean square error (LS) objectives, the mechanism works well with a result of 0.0046 as the average mean square error in the whole Munsell color space. The contribution of our approach not only lies in the accurate conversion from RGB to spectrum, but also in developing a set of color metamers for chromogenic methods of color calibration.