Lighting Color Rendering

Ways to Measure Color Rendering

The Color Rendering Index (CRI) is the most common numerical measure, ranging from 0 to 100, indicating a light source’s ability to accurately depict object colors compared to a natural or idealized light source, with higher values signifying better color rendering. However, based on limited color samples, this metric does not provide sufficient information on light spectrum and color-specific impact.

The R9 value indicates the ability of a light source to render the red color, crucial for applications such as art display, healthcare, and food display.

TM30 is a newer quality metric based on 99 color samples, providing measurements of color fidelity, saturation, and vibrancy.

CRI

Under 80: Poor color rendering

80 and 80+: Basic color rendering

90 and 90+: Great color rendering

Typically a 90+ CRI source will have a higher R9.

Industry standards asking for 90+ CRI: California Title 24 for residential; WELL Building Standard.

R9

Under 50: Poor red color rendering

70 or higher: Great red color rendering

90 and above: Excellent red color rendering

Industry standards asking for R9 50 minimum: California Title 24 for residential; WELL Building Standard; the U.S. GSA for public facilities.

TM30

Most accurate color rendering metric

Rf and Ra provide a similar indication as CRI.

Rg indicates color saturation and vibrancy.

Industry standards asking for min. Rf and Rg values: WELL Building Standard.