The Brightness & Color Meter measures color, color purity, degree of yellowness, degree of whiteness, color matching and color fastness. It also measures the effect of fluorescent additives by use of a removable ultra-violet filter. SPECIFICATIONS CIE 1931 (2 degrees) CIE 1964 (10 degrees), ISO 2469, 2470, 2471, ISO 5631.1 ISO