1. A color reproduction method that finds second color data, of a plurality of components represented in a second color system, corresponding to first color data of a plurality of components represented in a first color system, the second color system differing from the first color system, and the color reproduction method comprising: measuring each of colors represented by the second color data that correspond to a predetermined plurality of the first color data, and acquiring a plurality of sample data; targeting the respective components of the first color data corresponding to each of the acquired sample data, treating sample data corresponding to one target component as point sequence data in multiple dimensions, represented by a product of a number of components of the second color data and a number of the sample data of the respective components excluding the target component, and finding first control points which represent a characteristic of an approximation curve which approximates with the target components serving as parameters; thereafter targeting another of the components, treating the first control points corresponding to the target component as point sequence data in the multiple dimensions, and finding second control points which represent a characteristic of an approximation curve which approximates with the target components serving as parameters; sequentially altering the target component and finding final control points; and finding an interpolation equation from the final control points that have been found, for interpolating color data other than the sample data.