When Did Cooler Lighting Become Vital?

It has now been several decades that stores are using cooler lighting as an important driving force for sales. Initially, they used to light up the displays with T8 Fluorescent Tubes. But then came in LED lighting technology. It became an instant hit because a 41W LED fixture helped replace the 59W Fluorescent fixture. Since LEDs work efficiently in colder environments (which is exactly what is provided inside the display units), they tend to live more than the usual life expectancy.