The CRI value of a light source describes how accurately a light source illuminates colors of an object. It is scored on a scale with 100 being the best. Most standard bulbs have a CRI value of 80, while high CRI bulbs have a CRI value of 90 or higher.
For example, a painting shown under a 70 CRI light source may exhibit colors that don't appear correct, or accurate. When seen under a 95 CRI light source, however, the colors of the painting will likely look accurate and natural.