August 21, 2015: IES (Illuminating Engineering Society) has published a new technical memorandum called ?IES Method for Evaluating Light Source Color Rendition? that defines new color metrics for characterizing lighting.
TM-30-15 supplants CRI as a color metric. It relies on fidelity, gamut metrics, and a set of color samples that are like real-world objects, different from pastel samples that were used for the baseline CRI metric that was sometimes called Ra. TM-30 clearly provides an improved manner to evaluate light-source performance in the color area.
The new color metric accurately characterizes LED-based solid-state lighting (SSL) and legacy sources. The new Rf fidelity metric is similar to CRI, based on the new color samples. The new Rg gamut metric is evolved from the Gamut Area Index (GAI) work done original by the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute.
The publication of TM-30-15 does not automatically make it an industry standard; International Commission on Illumination (CIE) and the standards body behind CRI have to approve it.