In order to standardise not only the viewing environment but also factor „human“, special requirement are placed on the observer. The observer must be perceive colour normally and should have experience in colour comparison as well as a good ability to distiguish different colours. Corresponding visual tests help to choose suitable observers. In addition, a neutral colour such as gray must be worn during the colour assessment.
Two-dimensional sample plates need to be viewed with illumination of 0° by a viewing angle of 45° (measuring geometry 0°/45° and 45°/0° respectively). Howeder, certain application fields require different viewing and illumination angles, that is why appropriate sample holders are available in the web shop.
Colour differences are indicated to the ISO rating scale by hue, chroaticity and brightness. Finally, all details of the colour matching procedure should be recorded in an assessment report.