Lighting Research Center Lighting Research Center
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One of two identical mock-up display windows viewed by subjects in experiment. The other window featured a white background.

Color Kinetics

Colored Light in Display Windows (2002)

Colored Light Application in a Retail Display Window (2002)

A retail display window is typically designed to attract potential customers. In a shopping mall, display windows compete with one another to capture the attention of shoppers by using high light levels. It is common to see high illuminance ratios in the range of 15:1 to 30:1 between the display object and the background. A majority of retailers use halogen PAR or MR lamps in their display windows. High overall light levels and the use of inefficient halogen PAR and MR lamps in these applications results in increased energy use. The shortage and rising cost of energy in the United States has triggered many local governments to implement energy conservation programs. Therefore, a motivation for this study was to identify alternate lighting solutions for retailers that can lower energy consumption. The LRC hypothesized that the use of a colored light on the background of a display window would reduce the need for high light level accent lighting, resulting in energy savings.


The intent of this study was not to change the traditional white accent light to a colored light, but to use colored light on the background of the display window. Human subjects viewed two side-by-side, identical mock-up display windows, one with a colored background and the other with a white background, and rated their preference.

  • Subjects strongly preferred the colored background to the white background.
  • The use of colored light on the background allowed the accent light to be decreased without sacrificing visual appeal, the ability to capture attention, or the ability to see the displayed objects clearly. 
  • From the initial laboratory study, the amount of accent light can be reduced up to fifty percent, providing significant energy savings.

Mean preference rating. One the vertical axis scores below 0 are for the reference display (white background with 100% accent light), and scores above 0 are for the test desplay (colored and white background with varying amounts of accent light.

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