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CIE PS 002:2025 CIE Position Statement on Colour Quality Metrics, 2nd Edition

DOI
10.25039/PS.6qdfenyc

 

Characterizing white light sources for their colour rendering capabilities began in the 1960s, but both light sources and colour science have advanced considerably since then. 

This CIE Position Statement (PS) is the second edition on this topic, updating its 2015 predecessor. 

Key take-away points from this Position Statement are described below:

  • The CIE General Colour Fidelity Index (Rf) was developed in 2017 to remedy previously identified technical problems with the CIE General Colour Rendering Index (Ra).
  • At the time, the writers of CIE 224:2017 CIE 2017 Colour Fidelity Index for accurate scientific use recommended that the new metric be used for scientific purposes rather than industrial applications.
  • The new metric, Rf, has been used extensively with no evidence emerging to contradict its use.
  • The CIE recommends that the lighting community begin to adopt the CIE General Colour Fidelity Index, Rf, and to replace the CIE General Colour Rendering Index in relevant regulations, specifications, and standards.
  • In the interests of an orderly transition, the CIE recommends that both metrics be reported in parallel until the new metric is widely established.
  • A complete understanding of colour quality will require the development of additional new metrics for colour preference. This work is ongoing.

The full document of this CIE Position Statement can be viewed and downloaded here.