WHAT IS CRI
AND WHY DOES IT MATTER
What is CRI and why does it matter?
Colour Rendering Index (CRI) is a measurement used to indicate how accurately a light source reveals the colours of objects compared with a natural or reference light source.
CRI is measured on a scale from 0 to 100, with a higher score indicating more accurate colour rendering. A CRI Level of 100 represents the closest possible reproduction of colours under the chosen reference source.
Traditional CRI is calculated using eight standard colour samples, known as R1–R8, which are viewed under the test light source and compared with how they appear under a reference source at the same Correlated Colour Temperature (CCT).
The higher the CRI, the more natural and accurate colours will generally appear. High-CRI lighting can therefore make materials, finishes, furnishings and architectural features look much closer to how they would appear under high-quality natural or reference light.
Which Addlux Products offer the highest CRI Levels?
For projects where accurate colour reproduction is essential, Addlux CREOLUX LED Sheets and Bespoke LED Light Sheets offer some a range of CRI Levels to suit almost any application.
Whilst Addlux offers LED lighting solutions with high CRI levels, the highest CRI is not always the best choice for every project.
Effective lighting specification is about finding the right balance between colour rendering, efficiency, brightness and colour temperature, based on the material being illuminated, the environment and the intended visual effect.
Both Creolux flexible, cuttable LED sheets and our bespoke LED Light Sheet solutions offer standard CRI levels in excess of 80 or 90.
These provide an effective balance of colour quality and lighting performance for a wide range of architectural, interior and commercial applications.
Where more accurate colour reproduction is needed, Addlux can provide Creolux LED Sheets engineered to offer CRI values of up to 98, ideal for lighting applications or when backlighting natural stone such as onyx and marble. However, in some situations greater efficiency, higher light output or a specific colour temperature may take priority over achieving the highest possible CRI.
How does CRI affect Lighting Design?
CRI is an important consideration when specifying lighting because light does more than simply make a space brighter – it directly affects how we perceive the colours, textures and finishes within that space.
High-CRI lighting helps colours appear natural, vibrant and consistent, making it particularly valuable in environments where appearance and colour accuracy matter. This includes retail stores, galleries, hospitality interiors, healthcare environments, residential spaces and architectural installations.
Choosing the appropriate CRI can help ensure that carefully selected materials, finishes, furniture and products are presented as intended rather than appearing washed out, dull or noticeably different under artificial light.
What effect does CRI have on colours and materials?
The CRI of a light source can have a significant impact on how we perceive our surroundings.
Under lower-CRI lighting, colours may appear dull, muted or distorted. Two materials that look very different in daylight may become more difficult to distinguish, while certain colours can lose their natural richness and depth.
Under higher-CRI lighting, colours generally appear more faithful to their intended appearance. Details in materials such as natural stone, timber, fabrics, artwork and decorative surfaces can become easier to appreciate.
This makes CRI particularly important for applications where the appearance of materials and colours forms an important part of the overall design.
Applications where CRI is important
Retail Environments
Accurate colour rendering can significantly influence how customers perceive products. High-CRI lighting helps clothing, cosmetics, furniture, food and other merchandise appear more natural and representative of their true colours, creating a more appealing retail environment.
Art Galleries & Musuems
Artwork contains subtle differences in colour, texture and tone that can be affected by artificial lighting. High-CRI illumination helps reproduce these details more faithfully, allowing visitors to experience artwork closer to the artist’s intended appearance.
Healthcare Facilties
Good colour rendering can be particularly important in healthcare environments where visual clarity and accurate observation are required. Appropriate high-CRI lighting can also contribute to a brighter, more comfortable environment for patients and healthcare professionals.
Residential Spaces
High-CRI lighting can enhance the appearance of furniture, artwork, natural materials and interior finishes. Colours can appear richer and more natural, helping carefully designed residential interiors look their best throughout the day and evening.
Understanding CRI Ratings
CRI values range from 0 to 100, but the appropriate rating will depend on the application and the importance of colour accuracy.
Low CRI (Below 70)
Low or Poor CRI lighting can noticeably distort colours, making them appear dull, unnatural or significantly different from their appearance under higher-quality light. It is generally unsuitable for applications where colour accuracy is important.
Moderate CRI (70-79)
Moderate CRI lighting (70-79) provides improved colour rendering and may be adequate for applications where accurate colour reproduction is not a priority. However, differences in certain colours and materials may still be noticeable.
High CRI (80-100)
High CRI lighting provides significantly better colour reproduction. CRI 80+ is commonly used for general lighting, while CRI 90+ or 95+ is often preferred for architectural interiors, retail, hospitality, and other applications where colour quality is particularly important.
It is also worth remembering that a higher CRI is not automatically required for every project. The correct specification should balance colour quality with factors such as brightness, efficiency, CCT, application and the desired visual effect.
How are CRI Levels Measured?
Traditional CRI uses 15 standard colour samples (R1–R15) to assess colour rendering. The commonly quoted average value, known as Ra, expresses the performance of a light source based specifically on the accurate appearance of the eight initial standard colours, R1–R8.
Each of these colour samples is viewed under the light source being tested and compared with its appearance under an appropriate reference illuminant. The differences are used to calculate individual colour-rendering values, with R1–R8 averaged to produce the general CRI (Ra) value.
A higher Ra value indicates that the light source reproduces these standard colours more closely to the reference source, with values approaching 100 representing greater colour fidelity.
However, Ra alone does not describe every aspect of colour quality. The additional samples R9–R15 provide useful information about the rendering of specific colours. R9, for example, measures the reproduction of strong red tones and can be particularly important when illuminating skin tones, food, fabrics, artwork and certain interior finishes.
Can LED technology improve CRI Levels?
Modern LED technology has significantly improved the colour-rendering capabilities of energy-efficient lighting.
Early LED products could sometimes compromise colour quality in favour of efficiency or brightness. Today, advances in LED chips, phosphor technology and lighting design make it possible to achieve high CRI alongside excellent efficiency, brightness and colour consistency.
This has expanded the use of high-CRI LED lighting across architectural, residential, retail, hospitality and specialist applications where both performance and visual quality are required. Designers can also specify LEDs across different colour temperatures, outputs and control options while maintaining a high level of colour accuracy.
What is the Future of CRI in Lighting Design?
As LED technology continues to develop, lighting specification will become increasingly sophisticated.
CRI levels will remain an important measurement, but it will increasingly be considered it alongside other characteristics including R9 values, colour consistency, spectral quality, CCT, efficiency, brightness, glare and controllability.
The result is a more considered approach to lighting design in which the objective is not simply to provide sufficient illumination, but to create light that accurately complements the materials, colours and purpose of a space.
For architects, designers & lighting professionals, understanding these characteristics make it possible to specify lighting that delivers visual quality, performance & energy efficiency.
Conclusion
Colour Rendering Index is an important factor when choosing LED lighting, particularly where the accurate appearance of colours, materials and finishes matters.
From retail displays and hospitality interiors to residential spaces, artwork, natural stone and architectural features, selecting the appropriate CRI can dramatically influence the finished appearance of a project.
Higher CRI values generally provide more accurate and natural colour reproduction, but CRI should never be considered in isolation. colour temperature, brightness, efficiency, R9, installation method and the materials being illuminated should all form part of the lighting specification.
Understanding these factors allows designers and specifiers to choose LED lighting that does more than illuminate a space — it helps ensure that the colours, textures and materials within it are experienced as intended.
Contact one of our team today to discuss your requirements.
