The CIE Colour Rendering Index (CRI) (CIE 13.3-1995) and the general colour rendering index, Ra, has for many years been the standard metric for the colour rendition performance of light sources, included in a wide array of international and national standards, directives, regulatory documents and specifications. For some time, however, it has been recognised that the CRI presents limitations particularly for solid state light sources due to their rather different spectral distribution compared to traditional sources.
In 2015, the Illuminating Engineering Society (IES) published IES TM-30-15, which defines a comprehensive new approach based on ninety-nine reference colour samples, reporting fidelity Index (Rf), gamut Index (Rg), and the visual respresentation colour vector graphic. This has been well accepted by the lighting industry but has not yet been adopted by standardisation.
Now that the CIE has published CIE 224:2017, "CIE 2017 Colour Fidelity Index for accurate scientific use", based on the work of IES TM-30-15, does this signal the demise of the loved (and sometimes hated) CRI?