1. A tone evaluation apparatus which evaluates a tone reproduced using a color conversion table for converting image data on a first color space into image data on a second color space, the apparatus comprising: an acquisition unit adapted to acquire color information on the second color space for each of a plurality of grid points in the first color space; a calculation unit adapted to calculate a tone evaluation value for the color conversion table on the basis of a variation of curvature indicating a bending degree of a curve of the color information between the grid points in the first color space; and an evaluation unit adapted to evaluate a tone, reproduced using the color conversion table, on the basis of the tone evaluation value.