The Whiteness and Color Tester is a multi-functional optical property testing instrument widely used in industries such as papermaking, printing, textile dyeing, ceramics, building materials, chemicals, grain, and salt production. It measures blue-light whiteness, Hunter whiteness, yellowness, color, and color difference, as well as paper opacity, transparency, light scattering coefficient, light absorption coefficient, and ink absorption value. The instrument uses a simulated D65 illuminant and d/o illumination viewing geometry (integrating sphere diameter 150mm, measurement port diameter 25mm) with a built-in light absorber to eliminate specular reflection effects. It adopts the CIE 1964 supplementary colorimetric system and CIE 1976 (L*a*b*) color space formula. Measurement repeatability is ≤0.10 with high accuracy. The instrument stores up to 10 reference sample values in non-volatile memory, supports digital display and report printing. Compliant with dozens of national and international standards including GB/T 7973, GB/T 7974, ISO 2470, and ISO 2471, it is the standardized instrument for whiteness and color testing across multiple industries.