With the colour rendering index (CRI or Ra) of a light, you can assess how faithfully it reproduces the colours of its surroundings. We are used to excellent values from incandescent bulbs, as these have a full light spectrum with all colour components, comparable to sunlight.
Conventional incandescent bulbs and halogen bulbs are characterised by top values of up to CRI 100! Energy-saving and LED bulbs do not quite achieve the same quality of light, but they are very close.
If you value true-to-life colour rendering, you should only buy lights with a colour rendering index of at least CRI 90. For many lights, the colour rendering index is given as 80 CRI, which is too low for gourmets and foodies, for example, who don't want to see their food in distorted hues.
