The Color Rendering Index (CRI) measures how accurately a light source reveals the true colors of objects compared to a natural reference light (incandescent or daylight). The scale runs from 0 to 100, with 100 being perfect color rendering. A CRI of 80+ is considered good for general commercial use; 90+ is excellent for applications requiring accurate color, such as retail, healthcare, art galleries and printing. Low CRI lighting (below 70) makes colors appear washed out, distorted or unnatural. CRI is especially important when people need to distinguish color differences, such as in a clothing store, paint shop or medical examination room. Always check both the general CRI (Ra) and the R9 value (saturated red rendering).