Colour rendering

The quality with which colours are rendered under a given lighting. The degree of colour distortion relative to a reference light source can be expressed by means of metrics. The Ra value compares the light source under test with a reference light source on the basis of 8 reference colours. As an alternative to the Ra method, TM-30 defines the values Rf (fidelity) and Rg (gamut - saturation). Unlike Ra, Rf is based on 99 reference colours.