The Science of Light and Its Impact on Paint Color, Specification, and IEQ

Using artificial and natural lighting to help specify paint for healthy spaces
Sponsored by Benjamin Moore & Co.
By Andrew A. Hunt
1 AIA LU/HSW; 1 IDCEC CEU/HSW; 1 GBCI CE Hour; 0.1 ICC CEU; 0.1 IACET CEU*; 1 AIBD P-CE; AAA 1 Structured Learning Hour; This course can be self-reported to the AANB, as per their CE Guidelines; AAPEI 1 Structured Learning Hour; This course can be self-reported to the AIBC, as per their CE Guidelines.; MAA 1 Structured Learning Hour; This course can be self-reported to the NLAA.; This course can be self-reported to the NSAA; NWTAA 1 Structured Learning Hour; OAA 1 Learning Hour; SAA 1 Hour of Core Learning

Learning Objectives:

  1. Describe how color affects the symbolic, emotional or associative perceptions of occupants, and in turn, their health, safety and well-being.
  2. Explain how correlated color temperature (CCT), color rendering index (CRI), and spectral power distribution (SPD) impact the quality and color of light.
  3. Distinguish the CCT and CRI of different artificial light sources, and describe their effects on color.
  4. Provide examples of how design professionals can use their knowledge of light to create designs that support the health and well-being of the occupant.

This course is part of the Interiors Academy

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Compact fluorescent lighting was designed specifically to replace incandescent bulbs. CFLs entered the market in 1979. The great advantages of CFLs over incandescents are their energy efficiency and long service life. CFLs use 75 percent less energy than incandescents, with a 23 to 27-watt CFL providing the same light output as a traditional 100-watt incandescent bulb.

Fluorescents have some disadvantages. One is the warm-up time required. CFLs require thirty seconds or longer to achieve full brightness.

Over the years, the U.S. Department of Energy has upgraded efficiency standards for fluorescent fixtures. A 2010 rule effectively phased out T12 fluorescent fixtures in favor of T8 and T5 systems, which are much more energy efficient.

More recently, the U.S. Department of Energy mandated that all “general service fluorescent lamps” manufactured after Jan. 26, 2018, meet increased efficacy standards, as measured by lumens per watt. This rule eliminated 32-watt T8 systems, which did not meet the standards, and encouraged the adoption of either 25W or 28W T8s or LED T8 replacements.

Photo courtesy of Benjamin Moore & Co.

Light-Emitting Diodes (LEDs)

LEDs are available in a wide range of color temperatures from 2700K to 7000K and offer CRIs of 80 or higher. Warm white LEDs are crisp and the colors are vivid; cool whites tend to emphasize greens, blues, and violets.

LEDs are extremely energy efficient. With a life span that ranges from 30,000 to 50,000 hours, a typical LED will last up to four times longer than a CFL or fluorescent and 25 times longer than an incandescent source. What’s more, the life span of LEDs is not effected by the number of times they are turned on and off. In the United States alone, LED technology is expected to contribute to approximately 40 percent lighting electricity savings by 2030.

Aside from their energy efficiency, LEDs hold several other advantages. When LED lamps are dimmed, the color temperature remains relatively consistent. Unlike CFLs or fluorescent tubes, which require a warm-up time, LEDs achieve full brightness instantly. LEDs also contain no mercury or UV radiation.

Photo courtesy of Benjamin Moore & Co.

Natural Light and Daylighting

Few can argue against the appeal of a room flooded with natural light. In fact, daylighting can promote energy efficiency and occupant well-being, so long as glare and unwanted solar gain are controlled.

Natural light can have a significant and usually positive impact on color, but it is dependent on the room orientation and angle of the light. Light in north-facing rooms tends to be diffuse and cool. Hence, strong colors show well in these rooms, while lighter colors tend to look subdued.

South-facing rooms receive the most light, which can be a problem if left uncontrolled. However, these rooms lend themselves to a range of colors, whether cool or warm.

East and west-facing rooms have particular challenges. Light changes the most in these spaces. East-facing rooms benefit from warm morning light, but colors cool off as the sun moves higher. Similarly, west-facing rooms enjoy warm late afternoon and evening light, but colors may appear dull earlier in the day. In general, warm colors work well for these spaces.

A History of Health and Well-Being Research

Former University of Michigan psychology professors Rachel and Steven Kaplan have done a multitude of studies on how light impacts the health and well-being of humans. In the 1989 study titled “The Experience of Nature: A Psychological Perspective,” Kaplan and Kaplan found that when human enter a new environment, they cognitively search for elements that match their memories. This is how humans interpret new spaces and it is the brain’s way of being able to settle in and find comfort. Those memory-matching qualities might include spaces that remind us of childhood or another familiar context that makes us feel safe, welcome, and even joyful. Lighting is an important aspect of that experience. Light can be used to highlight any elements that induce familiarity, such as color, texture, and the shape of the space itself. For example, the way a brick wall is lit could remind a person of their neighborhood cafe. A framed art piece lit in just the right way could transport a person back to their childhood home.

For this reason, light is more than just a visual effect. It creates image, shape, intensity, perception, and contrast, but it can also deeply affect how a person experiences the space. It can improve or disrupt our sleep. It can impact our mood in either negative or positive ways. Studies have shown that light has the power to decrease depression and increase cognitive performance in measurable ways.

Brightness, hue, and saturation can evoke a wide range of emotions. Blue/white light has shown to make people feel more energetic, but can disrupt sleep patters around bedtime. Red/amber light is the least likely to disrupt sleep because it increases the secretion of melatonin, leading to better sleep and better cognition for the following day.

Colors themselves have a variety of associations. Black in interior design can increase a sense of strength, authority, elegance, mystery, aggression, and other moods, depending on how it is lit and used. Green can be used to evoke a sense of nature, health, calm and an array of other feelings.

Another area in which light and color can impact health and well-being is with seasonal affective disorder (SAD). SAD is a mood disorder that causes symptoms of depression during certain times of year, especially winter. It is a disorder than can affect anyone, even those without a history of depression. Light therapy is a common treatment of the disorder and is used to mimic natural light during dark and dreary days. Lighting and its interaction with color has the potential to create better environments for those suffering from SAD.


Just as the lighting source can have an impact on how a painted surface appears, so can the type of finish and the composition of the paint itself.

All paints include four main components: resins (or binders), colorants and pigments, solvents, and additives.

Resins and binders hold the pigment particles together and provide film integrity and adhesion. Colorants and pigments provide color and hiding. They also protect the underlying substrate, control gloss and sheen, and provide other performance attributes.

Solvents thin the coating for easy spreading and application and evaporate as the coating dries. Additives provide specific properties such as mildew resistance, viscosity, and foam control.

The balance and quality of these four ingredients impact the paint’s properties. And finally, the overall quality of the color can affect the psychology of an occupant, and result in health and wellness impacts.

This test is no longer available for credit
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Originally published in Architectural Record
Originally published in June 2022