What are the standard comparisons used to evaluate the colour quality of light sources?
Colour Rendering Index - CRI indicates the accuracy with which a light source such as an LED can reveal the various colours of an object. The standard CRI system is based on eight colours across the spectrum.
Additional R-values of CRI are used to represent certain colours. The appropriate R-values are application specific. For example R9 represents red and is good for lighting for lighting flesh. It also tends to make the light Warmer.
Colour Quality Scale CQS is a new system that uses a wider palette of 15 reference colours as against the smaller palette of 8 reference colours used for the CRI system.