Properties of a light source, for the purpose of color reproduction, are valued using “Color Rendering Index” (IRC or CRI-Color Rendering Index).
This factor is determined comparing objects color appearance illuminated by a given source, with color appearance illuminated by a “reference light”.
Incandescent lamps spectrals daylight are called “continuous” because they contain all radiations into the visible spectrum and are considered optimal in terms of color reproduction; It is said to have an IRC = 100.
Graphs of spectral distribution
These “graphics or spectral distribution curves” allow the designer to have a rapid appreciation about color characteristics of a particular source. Based on this criterion, artificial light sources are classified.
It will be said that a lamp has an excellent color rendering if the IRC is between 85 and 100, good if you are between 70 and 85 and discreet if it is between 50 and 70.
Keep in mind that two sources can have the same IRC and other “color temperature”.
Therefore it is appropriate, when color rendering capacity is compare, find that the lamps are approximate temperature of color. Obviously, for the same IRC, a red object will look brighter under 2800 K and not 7500 K.