What does CRI stand for and why is it important?

• A. Color Rendering Index; it measures how accurately a light source reveals colors compared with natural light.
• B. Color Reflection Index; it assesses how bright colors appear.
• C. Color Reproduction Indicator; it tracks the speed of color rendering.
• D. Color Radius Index; it evaluates the warmth of the light.

Answer: (A)

Color Rendering Index, or CRI, measures how accurately a light source reveals colors compared with a reference light. The score, from 0 to 100, indicates how true colors will look under that light—the higher the number, the more colors appear as they would under natural daylight. A perfect match would be 100, and most good interior lighting falls in the 80s or 90s, which helps paints, fabrics, artwork, and furnishings read as their true colors.

This matters because accurate color perception in a space affects how furniture, finishes, and decor actually appear. If CRI is low, colors can look washed out or biased toward certain hues, making it hard to judge color choices or achieve the intended mood. CRI focuses on a standard set of color samples, so while a high CRI is a strong indicator of good color rendition, it doesn’t capture every possible color interaction; some hues may still render differently under certain lights. For a fuller view, you might also consider extended measures or newer metrics like TM-30.