Art-PRO-ScienceLights
People are sensitive to color and color preferences are becoming a factor in the quality-of-life quotient. It has been shown that within a total environment the ideal is to include a variety of hues representing different degrees of brightness, saturation and temperature.

While one doesn't have to be a scientist to use color effectively, volumes of research on the subject has made life easier for many designers. Effective use of color has made multi-housing properties more appealing to prospective tenants and residents, encouraged workers to be more productive in office and manufacturing environments, and boosted patrons' positive experiences in restaurants and retail establishments.

Strategies based on color perception are familiar territory

The psycho-physiological effects of color are well documented, so careful consideration of what colors are selected — and in what combination — can help ensure desired results. People are sensitive to color and color preferences are becoming more sophisticated, in part because of television programs and consumer magazines where color is part and parcel of the quality-of-life quotient. The cheering effects of yellow, the relaxing qualities of green and blue, and the stimulating properties of red and orange cannot be overlooked. Used inappropriately, stimulating colors can be over-exciting or fatiguing, cool colors can be bleak and warm colors can be, well, too warm, causing people to feel hot.

Overall, it has been shown that within a total environment the ideal is to include a variety of hues representing different degrees of brightness, saturation and temperature.

Research has also explored how color influences our perception of size, weight and volume. Light hues and pale shades recede, while dark and saturated colors reduce the apparent size of a room or object. Warm colors are perceived as heavier than cool colors; that's why low ceilings painted in white or light colors work so well and high ceilings, which can stand some visual lowering, will work well in a darker hue, creating a more intimate feeling.

In the same way, combinations of colors and contrasting tones can be used very successfully to define spaces and provide direction. Medical facilities have used color codes to guide visitors and staff for years because it works. Shopping malls use contrasting floor colors at entrances and to guide traffic flow.

Practical applications for the use of color in certain ways are based on decades of research, and much of the information has been incorporated into the design world's base of knowledge. How differing light sources affect color is not as widely understood by designers, especially since scientific advances are continuously bringing new lighting technologies into the marketplace.

Color and light equals another color, sometimes

A designer's nightmare is for a client to approve a color recommendation and complain later that it's not the same color. The chief culprit? Probably the lighting.

For all practical purposes, when you mix color and light, you are mixing two colors together. Different types of light have color temperatures of their own which can play a crucial role in the perception of the colors you have selected for a project.

Color shifts are typically the result of several characteristics of the light source, primarily: the color rendering index and the color temperature.

The color-rendering index indicates how well a color is rendered under artificial light, compared with the color under a reference light source. The CRI uses a scale of zero to 100 — the higher the number, the less color shift or distortion. Natural outdoor light, incandescent filament light and Tungsten Halogen light have a CRI in the range of 95-100. Fluorescent lights range from the low 50s, for "warm-white" bulbs; to the 60s, for "cool-white" bulbs; and even the high 80s, for "deluxe cool-white" bulbs.

Color temperature indicates the color appearance of a light source. Basically it is the measurement of the whiteness of a light source, based on the principal that as an object heats up it will transform from glowing red to yellow, white, pale blue, then a brilliant blue. The temperature is measured in degrees Kelvin.

Technically, color temperature only applies to natural light sources, such as sunlight and incandescent lamps. Apparent (or correlated) color temperature applies to other light sources.

Compare the following: Incandescent lights range from 2,600-3,200 degrees K. Warm-white fluorescent is 3,000 K. Tungsten Halogen lamps range 3,000-3,400 K. Sunlight at noon is approximately 4,800-5,000 K. "Daylight" fluorescent is 6,500-7,000 K.

It may seem contrary, but warm color light sources have lower color temperatures and cool color lamps have higher color temperatures. Cool color lighting in the 4,000 K and higher range is typically recommended for offices and business environments. Warm tones in the 3,000 K and lower range are routinely used in residential environments and other spaces requiring a warm, inviting atmosphere. Lamps in the 3,000-4,000 K range are considered neutral.

Light — work with it or make it work for you

It becomes readily apparent then, when CRI and color temperature are considered, that there are vast differences between light sources and how they can affect color. The adroit designer factors in these variables, either by selecting and coordinating colors in the light in which they will be used or by selecting the desired colors and specifying lighting that will allow the colors to remain true.

Want to take on a real creative lighting challenge? Use mixed lighting sources. For example, designers working on projects where windows are a factor are faced with several additional challenges — multiple light changes. Daylight varies from morning to night, from season to season, and by geographic orientation (north, south, east or west). In many cases artificial light sources may be used to supplement daylight ambience and replace it at night. Not only is it important for designers to understand light and its effects on color, but clients who have some understanding, as well, are more accepting of variations in perceived color.

Clever designers can also use the color and temperature attributes of artificial lighting to purposely modify color. Specifying incandescent lamps will intensify yellows. Cool fluorescents, which are blue in tone, will make yellows appear greener. The bright white of a halogen light can intensify colors.

Another phenomenon related to light and color is metamerism. It's the phenomenon where two materials will appear to match under one light source and not match at all under another. When this occurs the color match is said to be "conditional." Metamerism can occur for a variety of reasons, such as when the colored objects have different reflective surfaces — say, paint and fabric or wallpaper and carpet — or when different combinations of pigments or dyes are used to achieve a color, or if the formulas have different physical or chemical characteristics. However, if the reflectance spectra of the two objects are identical, they cannot be metameric and are regarded as an "unconditional" match.

Color and light play key roles in our lives, and with regard to each other. Without light, there would be no color. Without the scientific research compiled on the subject, we'd still be in the dark about color's effects on us and light's effects on color. Color science is a valuable tool for designers and color experts, no matter what the assignment.

Color perceptions at-a-glance

Red: Dynamic, exciting and stimulating.

Orange: Mellower than red, yet still stimulating and warm; friendly.

Yellow: Cheerful, radiant, happy, uplifting.

Green: Relaxing, refreshing, tranquil.

Blue: Calming, comforting, cooling, peaceful.

Violet: Dignified, rich, noble, intense.

Cool colors: Greens, blues and violets; tend to recede and make rooms appear larger and spacious.

Warm colors: Yellows, reds and oranges; seem to advance and make a room feel smaller and more intimate.

ARTIFICIAL LIGHT SOURCES

Lamp Type Approx. Color Rendering Index Approx. Color Temp. (degrees K)
Incandescent 95-100 2,600-3,200
Tungsten Halogen 95-100 3,000-3,400
Xenon 95 6,000
Fluorescent — Deluxe cool-white 89 4,200
Fluorescent — Daylight 75-79 6,500-7,000
Daylight Metal Halide 70 6,500
Fluorescent — Cool-white 65 4,200-4,500
Fluorescent — White 60 3,400-3,500
Compact Metal Halide 60-90 3,700-3,800
Fluorescent — Warm-white 52 2,900-3,000
High pressure sodium 22-65 2,000-3,200
Mercury 15-55 4,000-6,500
Low pressure sodium 0 1,600-2,000