Technical resource
Colour quality: CCT, CRI, R9 and TM-30
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.
Technical review: LUMIBRIGHT technical team · Lighting application engineering · Revision 2026-09-26
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.
