Under the influence of metamer mismatching, one color under a standard illuminant can become various colors under a test illuminant, which challenges color constancy phenomenon. In order to investigate the effect of metamer mismatching on color constancy in two-dimensional simulated scenes, we analyzed color constancy data obtained in asymmetric color matching performed on a CRT monitor in the context of metamer mismatching. The results showed that color constancy indices of Munsell surfaces had almost no correlations with metamer mismatching indices under each chromatic illuminant. The matched points of observers were close to the theoretical points based on traditional perfect color constancy rather than metamer mismatch centroid chromaticities. The results indicate that observers’ matching is not affected by metamer mismatching degrees of surfaces; in asymmetric color matching, observers tried to find a chromaticity point which was produced by a spectral reflectance close to that of the standard surface under a chromatic illuminant, rather than a centroid chromaticity point of metamer mismatch volume.