Lighting quality is not just about brightness—it’s also about how natural and pleasing the colors appear under that light. For decades the standard in color rendition has been the Color Rendering Index (CRI). But with the advent of LED and solid-state lighting technologies, limitations of CRI became more apparent. The Illuminating Engineering Society (IES) introduced TM-30-15 in 2015 as a more comprehensive method for evaluating how light sources render colors.
TM-30-15 Contains 3 Main Components
| Component | Symbol | Purpose |
| 1. Fidelity Index | Rf | Measures how accurately colors are rendered vs. a reference. (0–100; similar to CRI Ra) |
| 2. Gamut Index | Rg | Measures average color saturation. (Rg = 100: neutral; >100: vivid; <100: muted) |
| 3. Color Vector Graphic | – | Visual map of hue & saturation shifts in 16 hue bins. |
Based on 99 Color Evaluation Samples (CES) — real-world objects (skin, food, textiles, etc.).
CRI vs TM-30-15
| Feature | CRI (Ra) | TM-30-15 (Rf/Rg) |
| Color Samples | 8 pastel | 99 real-world |
| Saturation Info | ❌ No | ✅ Rg |
| Visual Tool | ❌ No | ✅ Color Vector Graphic |
| Color Space | 1960s 2D | Modern 3D (CAM02-UCS) |
| Gaming Risk | High (optimize for 8 peaks) | Low (99 samples) |
Example: Two lights with CRI = 90 can look vivid vs. dull — TM-30-15’s Rg reveals the difference.
Why is TM-30-15 Important?
- CRI is outdated — poor with LEDs, ignores saturation, weak on reds.
- More accurate & predictive — 99 samples + modern color science.
- Enables preference-based design — High Rf ≠ always preferred (e.g., retail wants Rg > 100).
- Industry standard in transition — Used by Bridgelux, Soraa, DOE, IES.
- Future-proof — Basis for TM-30-18 and TM-30-20.
Specifiers: Recommended Targets
| Application | Rf | Rg | Notes |
| Museums | ≥90 | 97–103 | Accurate art, high R9 |
| Retail (Fashion/Food) | 80–85 | 105–115 | Vivid colors |
| Offices/Healthcare | ≥85 | 95–105 | Natural skin |
| Hospitality | 80–90 | 100–110 | Warm & inviting |
Spec Tip: “Rf ≥ 85, Rg 100–110, no major red undersatu
Specifiers & How to Use It
Lighting specifiers, manufacturers, and designers can use TM-30-15 as follows:
- Specify minimum values of Rf and desired Rg for a given application.
- Evaluate light source performance not only by number (e.g., CRI > 90) but by how colors appear in context (appearance of fabrics, skin tones, products).
- Use the Color Vector Graphic to understand hue shifts and saturation changes, rather than relying solely on a single index.
- Recognize that there is no one “magic number” yet defined for all applications—context matters. For example, a food display may benefit from higher gamut (Rg > 100) to enhance meat reds, whereas an office may prioritize fidelity (Rf high) and neutral gamut.
Additional Resources
MSHLED is a professional LED light strip manufacturer, we produce high quality LED light strips and LED Neon Flex. You and check the below resources to understand TM-30-15 better.
FAQ
Conclusion
TM-30-15 marks a significant advancement in measuring color rendition in lighting. By offering broader sampling, modern color models, and expanded metrics, it provides a richer understanding of how light will affect surfaces and spaces. For lighting professionals seeking more than just a “CRI > 90” number, TM-30-15 offers improved transparency and guidance—helping you specify lighting that truly enhances color appearance and user experience.
All of our products go through high-tech laboratories to ensure the utmost quality. Besides, we offer customizable options on our LED strips and neon flex. contact MSHLED ASAP!
