What is the Colour Rendering Index?

Colour rendition is the ability of a light source to accurately illuminate a colour compared to a reference source.

How is this measured?
The current method uses a reference pallet of 8 colours (R1-R8) called the Colour Rendering Index (CRI) developed by the CIE. Latterly an additional 6 (R9-R14) more saturated colours have been added but do not have to be referenced. CRI is stated in terms of a factor of 100 e.g. CRI80 or CRI 90 and is an average of colours tested (Ra).

colour-rendering-index

What is the future of Colour Rendition?
The Lighting Industry has taken steps to move away from the CRI method as it is too limited and not a true representation of colour, especially with White LEDs.

What is TM-30?
The new TM-30 standard offers two metrics Colour Fidelity (Rf) and Colour Gamut (Rg). Colour fidelity is similar to CRI however references 100 swatches rather than 8.
Colour Gamut is the average level of saturation relative to a reference illuminate (measured between 60 and 140).