How to choose the best color temperature?
Two white lights can be completely different. Surely you have noticed when, after replacing a fused light bulb (something less and less frequent thanks to LED lighting), you have perceived the room differently. It is because you have placed a bulb, also white and of the same power, but with different color temperature.
The color temperature could be defined as the sensation that the human eye perceives about a light, being warm if the amber prevails or cold color if the blue predominates. This measurement only applies to white light and is technically defined as the “color printing at certain temperatures of a perfect black body radiator”, according to the guide of the Federation of European Luminaires and Components Associations for Luminaires. The concept is simpler than it seems.
Think of an incandescent iron that is getting more and more heat. When its temperature is about 1,000 K (Kelvin degrees) it takes on a reddish hue. If the temperature rises to between 2,000 and 3,000 K its color turns yellowish. At 4,000 K its tone is neutral white and between 5,000 and 7,000 K cold white. However, when we speak of light, “temperature” is only a relative measure: it has nothing to do with physical heat but with the sensation it produces in the human eye.