Reviewed by Frank Agraz, LC, IES — Director of Energy Services at Facility Solutions Group. Authored by Andrew Ghilino.
What is CRI?
Color Rendering Index (CRI) is a measure of how accurately colors appear under a light source compared to a natural or standard light source (such as daylight).
Why is CRI Important in Lighting?
- High CRI lighting boosts product appearance and shopper confidence.
- Reduces eye strain and can enhance productivity.
- Makes environments more comfortable and visually appealing in retail, hospitality, and workplace settings.
How is CRI Measured?
CRI is scored from 0 to 100. Higher values mean colors appear more faithfully, similar to natural daylight.
- A CRI of 85 in an office will render walls and furniture convincingly.
- A CRI of 95 in a boutique store makes product colors pop in photos and in person.
CRI Testing and Calculation:
- Eight standardized color samples are compared under the test light and reference light.
- Each is scored from 0–100. The general CRI is the average of these.
- Some manufacturers also include extended scores (like R9 for reds) for more detailed analysis—especially important in retail and hospitality.
Measuring the quality of lighting is more than just brightness, it’s also about how accurately colors appear under a light source.
In commercial facilities, from retail showrooms to corporate offices, CRI influences everything from product appearance to visual comfort. Deploying lighting with the right CRI through tailored commercial lighting services can boost shopper confidence, reduce eye strain, and even enhance productivity.
Visualizing the CRI Scale and Scoring System
See how different CRI’s affect the look of strawberries below.
Standard Testing and Calculation Methods
CRI values are determined by comparing the appearance of eight standardized color samples under the test light versus a reference light (incandescent or daylight, depending on color temperature). Each color is given a score from 0-100. The average of these eight scores yields the general CRI for the light source.
Some manufacturers also report extended color scores to give a more thorough analysis. R9, a CRI value that measures the color “red”, will occasionally appear in specification sheets to assist designers in selecting the proper light source for their project.
These extra scores help measure light sources that are important for retail and hospitality applications.
How Does CRI Compare to Other Lighting Metrics?
CRI vs. Correlated Color Temperature (CCT)
| Metric | What It Measures | Use |
|---|---|---|
| CRI | Accuracy of color appearance | Fidelity of product colors |
| CCT | Warmth/coolness of light (Kelvin) | Mood and ambiance |
- A light can have a high CRI but still be warm or cool in color tone.
- Example: A 3000K fixture (warm white) with CRI 95 offers warmth and faithful color—ideal for restaurants and retail.
A 3000K fixture (warm white) with a CRI of 80 will create a cozy feel but may not render blues and greens accurately. That same 3000K fixture with CRI 95 will offer both warmth and faithful color which is ideal for restaurants or retail clothing stores.
CRI vs. TM‑30
While CRI measures just 8 color samples, TM-30 measures 99, providing a more comprehensive measurement metric.
TM-30-20 is a new metric by the Illuminating Engineering Society, using 99 color samples.
- Fidelity Index (Rf): Similar to CRI but more comprehensive.
- Gamut Index (Rg): Measures saturation and hue shifts.
- Used increasingly in architectural lighting.
Although CRI still remains as the most common metric for measuring color quality, many manufacturers, especially in the architectural space, are including TM-30 data in their specification sheets. You can learn more about TM-30 on the IES website.
Recommended CRI Values by Application
| Application | Recommended CRI |
|---|---|
| Retail/Hospitality | 90+ |
| Offices/Classrooms | 80–90 |
| Galleries/Photography | 95 |
Retail and Hospitality Settings
High‑CRI lighting transforms merchandise displays. Apparel, jewelry, and home décor items look more vibrant. In hospitality applications, such as restaurants, bars, lobbies, guests feel more at ease, and food presentations appear more appetizing.
A CRI of 90+ is often recommended for premium retail and upscale dining.
Offices and Educational Facilities
In offices, accurate color rendering reduces visual fatigue and supports tasks like graphic design or product development. Educational facilities benefit from high CRI in art studios, labs, and media rooms, where students must distinguish subtle color variations.
A CRI of 80–90 is typically sufficient for general classrooms and conference rooms.
Choosing the Right CRI for Your Next Lighting Project
Selecting the right CRI hinges on your space’s function and budget.
| Color Rendering Index (CRI) | Quality |
|---|---|
| 0-70 | Very poor color rendering. Colors may appear washed out or distorted |
| 70-79 | Moderate color rendering. Good for some common & industrial areas. |
| 80-89 | Very good color rendering. Good for offices and lobbies. |
| 90-100 | Excellent color rendering. Ideal for retail, hospitality, galleries. |
- 80+: Standard commercial and industrial spaces.
- 90+: Retail, showrooms, galleries, and any color‑sensitive environments.
- 95+: Museums, high‑end retail, or photography studios.
Consult with lighting professionals to balance CRI with energy efficiency, fixture cost, and maintenance.
Work With a Lighting Expert That Understands Your Color Rendering Needs
Color Rendering Index may seem technical, but its impact is clear: better color fidelity leads to stronger brand experiences, happier occupants, and more productive spaces.
When you’re ready to upgrade to LED or CRI lighting, FSG is your certified trusted lighting expert. Our team of lighting designers and estimators will help you find lighting with the right CRI for your business.
Contact FSG today for a customized lighting consultation. Discover how energy‑efficient, high‑CRI lighting can transform your business today.
Frequently Asked Questions
What is considered a “good” CRI for LED lighting?
For most commercial spaces, 80+ CRI is considered a solid baseline, while 90+ CRI is recommended for retail, hospitality, and other color-sensitive environments. FSG notes that higher CRI improves color fidelity, which can impact everything from product appearance to visual comfort.
Why does CRI matter if my space already looks bright enough?
Brightness doesn’t guarantee accurate color. CRI measures how faithfully colors appear under a light source. The blog explains that higher CRI can reduce eye strain, improve comfort, and make products or finishes look more true-to-life even at the same light level.
What is R9, and why do lighting spec sheets sometimes include it?
R9 is an extended CRI score that specifically measures how well a light source renders strong reds, which the standard CRI average (R1–R8) doesn’t fully capture. The blog notes R9 is especially important in retail and hospitality, where accurate red tones influence how products, food, and skin tones appear.
Is CRI the same thing as color temperature (CCT)?
No. CRI measures color accuracy, while CCT (measured in Kelvin) describes whether light looks warm or cool. This FSG blog explains you can have warm light that’s low CRI (cozy but color-distorting) or warm light that’s high CRI (cozy and color-accurate).
Should I care about TM-30 instead of CRI when choosing lighting?
CRI is still the most common metric, but TM-30 is more detailed because it evaluates 99 color samples instead of 8, providing deeper insight into fidelity and saturation shifts. The blog notes TM-30 is becoming more common in architectural lighting specs, so it can be useful when color quality is critical.
Authored by Andrew Ghilino
Expert reviewed by Frank Agraz, LC, IES, Director of Energy Services at Facility Solutions Group, specializing in commercial lighting design and energy efficiency.
