Color evaluation will change based on how a sample is viewed.  A 45° viewing angle to the source is recommended to reduce shading and achieve consistent comparison.

Gloss is the general reflectivity of a surface, which encompasses a variety of degrees. One particular type of finish is high gloss, which has the maximum shine and reflectance. It increases the richness but emphasizes flaws as compared to satin or matte.

 A gloss test gauges the reflective quality of a surface by casting light at a fixed angle and measuring the amount reflected. It defines the level of shine or dullness of a surface, and it is very crucial in coatings, automotive, and product finishing

The machine used to measure color is primarily called a colorimeter or spectrophotometer. 

Spectrophotometer: The most common and precise type. It analyzes light reflected/transmitted by an object across the visible spectrum to quantify color accurately. A spectrophotometer can measure colors on smooth or matte surfaces, as well as textured, glossy, mirror-like surfaces, and special effect colors. It measures the reflected light of a sample at a fixed angle (e.g., 45˚) or captures light reflected at all angles to calculate color measurements that closely match what the human eye perceives. Additionally, similar to how humans flip a sample to view colors from different angles, a spectrophotometer is suitable for measuring a variety of materials and surface characteristics. Widely used in industries like paint, textiles, plastics, Chemicals, Pharmaceuticals, and printing. 

Colorimeter: Also called photoelectric integrating colorimeter, a simpler, more cost-effective option. It measures color based on three primary colors (RGB) and is suitable for basic color matching needs. A photoelectric integrating colorimeter is a color measurement device based on the photoelectric integration principle. It directly measures the tristimulus values XYZ of an object's color using three color filters (red, green, blue) and silicon photocells as three sensors. The color measurement principle of this instrument imitates the human eye's mechanism of perceiving the three primary colors (red, green, blue). It corrects the relative spectral sensitivity of the detector through color filters to match the CIE-recommended spectral tristimulus value functions x(λ), y(λ), and z(λ).

Spectrocolorimeter: Combines the functions of spectrophotometers and colorimeters, offering both spectral data and color space values for comprehensive analysis.

 Color is measured using devices such as colorimeters, spectrophotometers, and spectroradiometers. Colorimeters are easier and good for simple color quality tests. Whereas spectrophotometers yield detailed spectral information. Hence, suitable for laboratories and industries.

Ensure the source, viewing angle, and background are all neutral and standardized, and the samples are clean, and positioned for a side-by-side comparison under each light condition.

To extend the life of a haze meter, keep the instrument dust-free and clean, regularly calibrate it, and control for a stable dry storage. For better results, avoid letting the optics dry, and leave the meters under sunlight. For optimal performance, have the meter professionally serviced once a year.

 A gloss meter measures the amount of light reflected from a surface at a specific angle. It's commonly used to assess surface finishes such as paint, coatings, plastics, and paper for consistency, quality control, and visual appearance evaluation.

They provide accurate and repeatable assessments of color in various settings for the purpose of avoiding inconsistencies in mismatched items and ensuring steady production or branding.

The most common standard measuring gloss is ASTM D523, which covers the procedures of using a gloss meter at 20°, 60°, and 85° angles. The other international standard that is widely used in industrial and laboratory applications is the ISO 2813.