Achieving color constancy is an important step to support visual tasks. In general, a linear transformation using a 3 × 3 illuminant modeling matrix is applied in the RGB color space of a camera to achieve color balance. Most of the studies for color constancy adopt this linear model, but the relationship of illumination and the camera spectral sensitivity (CSS) is only partially understood. Therefore, in this paper, we analyze linear combination of the illumination spectrum and the CSS using hyperspectral data that have much more information than RGB. After estimating the illumination correction matrix we elucidate the accuracy dependence on illumination spectrum and the camera sensor response, which can be applied to CSS.