Color Rendering Index, or CRI, of a light bulb refers to how a specific light source makes the color of an object in the environment appear.
A light with a higher color rendering index allows one to see the subtle variations in its shades and hues. We express the CRI of a light source as a number on a scale ranging from 0 to 100. The higher the number is, the better is the ability of the lighting source to render the color details of an object accurately, and as the eye ideally perceives color as it should be seen.
Typically, great quality (and new energy efficient) lighting products should have a CRI of mini 80 or more than 90.