With the recent advances in color management systems, the estimation of accurate colorimetric values of objects being imaged by the use of sensor responses becomes an important function of color image acquisition devices such as digital cameras and color scanners. Therefore, colorimetric evaluation of a set of sensors is important to evaluate the colorimetric performance of the sensors. It is well known that the colorimetric quality of the sensors depends not only on the spectral sensitivities but also on the noise present in them. Although several evaluation models have been proposed, application of the models to real color image acquisition devices has not been appeared since it was impossible without prior knowledge about the noise present in the devices. In this article, a new model to estimate the noise variance of an image acquisition system is proposed based on the colorimetric evaluation model and for the first time the evaluation model was applied to real multispectral cameras by using the estimated noise variance. It is confirmed by the experiments that the proposed colorimetric quality is in good agreement with the experimental results and that the noise variance of the image acquisition system can be accurately estimated by the proposal.