Technical resource
Specify colour quality with the right evidence
Colour quality is four separate questions: how warm the light appears, how faithfully it renders colour overall, how it handles deep reds, and how saturation and hue shift across the whole spectrum.
Ra, R9, Rf and Rg are separate
CRI Ra summarizes rendering of the traditional general samples; saturated-red R9 is not included in Ra. TM-30 fidelity Rf and gamut Rg describe different properties and require a measured report. No R9 or TM-30 value is inferred from CRI.
CCT and consistency
Record CCT, tolerance and measured SDCM for the exact engine and operating conditions. High CRI alone does not establish low flicker, low glare, spectral suitability for every material or consistency across batches.
Controlled material mock-up
Compare skin tones, textiles, timber, stone, artwork or jewellery at matched CCT and output. Keep exposure and white balance fixed. Photographs have display and camera limitations; physical review remains important. Unpublished metrics remain unknown.
What specifiers ask
What does CCT describe?
Correlated colour temperature describes appearance, not quality: 2700K reads warm, 4000K neutral, 6000K cool. Keep one CCT within a sightline, and note that tunable white models cover a range rather than a fixed point.
What do CRI and R9 describe?
CRI is an average across eight pastel colours, so a high CRI can still render deep red poorly. R9 reports the red performance specifically and matters for food, timber, skin tones and retail textiles.
What does TM-30 add?
TM-30 reports fidelity (Rf) and gamut (Rg) across 99 samples, which describes saturation and hue shift more completely than CRI alone. We publish it where the model has been tested.
Which values are available for a chosen model?
The article table on each family page lists the CCT and CRI values actually supplied for that model. Where R9 or TM-30 data exists for a tested sample, the technical team can provide the report.
Related pages
Request the tested colour data for your shortlist
Send your reflected ceiling plan, room dimensions or lighting schedule. Include the project location, stage and required date so the team can confirm suitable models and the documentation available.