CRI, or Color Rendering Index, is a measure of how accurately a light source is able to reveal the intrinsic colors of what it is illuminating. Established in the 1960s, CRI is an extremely important measurement for assessing the color performance of a light source.
CRI testing is achieved by comparing eight color chips (R1 to R8) to a reference source of the same color temperature.
The CRI scale runs from 0 to 100, with a rating of 80 or above typically being most desirable for indoor lighting applications.