Color Rendering Index


Definition of Color Rendering Index

Color Rendering Index (CRI) measures the quality of light produced by a light fixture. It’s a measurement of how accurately a lamp illuminates colors compared to natural light and is expressed as a number ranging from 0–100, with 100 being the best possible value.

The sun is said to have a perfect 100 score on the index while tungsten (incandescent) has a near perfect score although it skews towards the red end of the color spectrum.

Historically, LEDs have had a low CRI often making colors appear grayish. With ongoing research to produce better white light, LED lights have come a long way in delivering excellent light quality with many of them now claiming an 80+ ranking on the index.

CRI isn’t an isolated characteristic of light and can be affected by:

  • Light spectrum: A light source with a more continuous and balanced light spectrum, such as high-quality LEDs, will generally have a higher CRI than a light source with a more limited or spiky spectrum, such as fluorescent lights.
  • Light temperature: Color temperature can shift the color appearance of objects. Generally, cooler light temperatures (5000K-6500K) have a higher CRI for daylight simulation, while warmer light temperatures (2700K-3000K) have a higher CRI for indoor lighting.
  • Light color: The color of the light source can affect the CRI because it can influence the color appearance of objects. A light source with a color that complements or enhances the color of the object being illuminated will generally have a higher CRI than a light source that clashes with the object's color.

Why would you want a high CRI score?

CRI is an important factor to consider, especially in situations where color accuracy is critical.

For example, navigational charts are color-coded and having cockpit lights with a high enough CRI can help you differentiate the safe shallow waters (blue) from the areas where your boat might run aground (green).

High CRI light, from 80–100 is essential for the following lighting types:

  • Ambient light: To give a more realistic rendering of color which is more comfortable to view
  • Accent lighting: To represent accurately the colors of whatever artwork, interior finish, or architectural detail being highlighted
  • Task lighting: To allow for accuracy and precision especially when dealing with color coded taks, such as wiring, chart reading, or bait rigging

The Lumitec Octane Spread Light has a CRI of 70+ making it ideal for both ambient and task lighting.

Example of Color Rendering Index in a Sentence

"The new LED light bulbs have a CRI of 90, providing vibrant colors in our yacht’s remodeled cabin."

Related Terms for Color Rendering Index