2021-01-132021-01-132015-11-20https://repository.tcu.edu/handle/116099117/42953https://journals.sagepub.com/doi/10.1177/1477153515617392It is well known that the colour of illuminated surfaces can look different under different light sources. In the mid-20th century, as the diversity of light sources began increasing, the Commission Internationale de l�Eclairage (CIE) developed a metric for assessing colour fidelity called the colour rendering index, or CRI. Since 1965, CIE CRI has estimated the colour fidelity of a light source for 14 selected sample surfaces, and also an average accuracy, Ra, for an eight-sample subset.enhttps://creativecommons.org/licenses/by-nc/3.0/light sourcescolorengineers' associationsuniform distribution (probability theory)social aspectsArticleCC BY-NC 3.0https://doi.org/10.1177/1477153515617392