The reconstruction of spectral reflectances of objects being imaged is important in reproducing a color under a variety of viewing illuminants. In this work, a simple formula is derived to evaluate the quality of a set of color image sensors aimed at reconstruction of spectral reflectances, and it is applied to multispectral image acquisition systems. Since the quality depends not only on the spectral sensitivities but also on the noise present in the systems, it is impossible to evaluate a set of sensors without prior knowledge of the noise present in it. Therefore, the noise variance of the multispectral cameras is estimated by a new proposal, and it is applied to the evaluation for the first time. It is shown that the experimental results agree well with the predictions by the evaluation model, and that the method to estimate the noise variance is useful for the evaluation.