Usage
RGB2XYZ(RGBmatrix, illuminant = "D65", observer = 2, RefWhite
                 = get("XYZperfectreflectingdiffuser", envir = environment()),
                 RGBModel = "sRGB", RefWhiteRGB = get("whitepointsRGB",
                 envir =environment()), gamma = NA,
                 RefWhiteIllum = get("XYZperfectreflectingdiffuser",
                 envir = environment()), CAT = "Bradford",
                 CATarray = get("ChromaticAdaptation", envir = environment()))