The colour rendering index, IRC or CRI, helps compare how a light shows the colours of objects against a reference. It is useful when choosing lighting for clothes, food, wood or finishes. To make use of it, read the figure alongside the task and the specific model's documentation.
This guide helps distinguish between information sufficient for an everyday purchase and details worth requesting when colour is critical. The aim is to compare options thoughtfully, without attributing performance based on a photograph or phrases such as “quality light”.
IRC is the Spanish abbreviation, while CRI is the usual English term. In commercial specifications, they generally refer to the general index Ra. The CIE defines Ra as the average of the indices for eight test colour samples.
A value of 90 does not mean that 90% of colours are rendered correctly. It is the result of a comparison against a reference. Nor does it measure how much light reaches a table, how much electricity the fitting uses or how long it will last.
The United States Department of Energy presents CRI 80 as a general guideline for interiors and CRI 90 or above as excellent colour fidelity. These are selection guidelines, rather than a guarantee that any product will meet a professional task's needs.
To choose, first describe the use. “Lighting a passageway” and “choosing between two upholstery samples” involve different requirements. In the second case, it is worth requesting additional information and checking the actual materials before installing many units.
| Situation | First criterion | Next check |
|---|---|---|
| General domestic use | The model's stated CRI | Distribution, comfort and quantity of light |
| Choosing clothes or finishes | Compare alternatives with documented fidelity | View the samples under the shortlisted options |
| Products where reds matter | Also check R9 | Request the value if it is missing from the specifications |
| Professional colour control | Define the task's technical requirements | Specialist validation and assessment conditions |
R9 evaluates a saturated red sample and is not included in the Ra average. The DOE technical fact sheet on colour characteristics explains why it can provide additional information, including when viewing skin tones.
If the project depends on red nuances, request CRI and R9 separately. When a shop publishes only Ra, leave R9 as “to be confirmed”. Avoid filling the field with an estimated value or assuming that a high Ra guarantees every result for red.
The NIST explanation highlights a limitation of averaging: a high overall score can coexist with poorer rendering of specific colours. It also distinguishes colour fidelity from other matters, such as the observer's preferences.
That is why two fittings with the same CRI can create different impressions. If one model lacks information, do not conclude that it is better or worse than another: mark the comparison as incomplete. Ask for documentation identified with the model and keep the response with the quotation.
Colour temperature describes another aspect of light. Note it to compare equivalent options, but do not infer CRI from kelvins. The beam angle also affects how the object is illuminated, although it cannot be used to calculate colour rendering.
Imagine you are lighting a corner where you choose textiles. Prepare three samples you actually use: a light one, a dark one and one with an important red. Note the differences you need to distinguish, such as two similar shades or the contrast between fabric and stitching.
The test guides your choice, but does not replace a technical test or a professional colour-control procedure. A phone photograph can help you remember the setup; automatic image processing prevents it from being used as a colour certificate.
These examples help distinguish a published figure from one awaiting confirmation. They are not presented as CRI 90 products or as recommendations for demanding colour work.
The specifications state CRI 80. They do not publish R9 or establish CRI 90. Use this figure as a starting point and request additional information if your project depends on specific colours.
View product details and options
The description consulted does not state CRI or R9. Request both figures when relevant; its 3000 K and reading function do not establish colour fidelity.
View product details and optionsNo. CRI compares colour fidelity. The warm or cool appearance of light is described by other data.
No. If distinguishing them matters, check both samples under the intended lighting and define the assessment conditions.
Request the figure for the specific model. Missing information does not justify automatically assigning CRI 80 or CRI 90.
No. It complements the information with data about a specific red sample; both figures should be interpreted according to the application.
It is a different criterion. See the guide to energy labels and EPREL to review efficiency and documentation.
Complete your purchase by reviewing maintenance for integrated LEDs and replaceable bulbs. Continue with the lighting guide index.
