Interior Lighting for Designers

be the same color under a certain light
source although they are different in spectral
composition. If the light source is changed,
however, the object color differences become
apparent (color plate 11).
It is advisable to appraise, match, and
specify colored materials using light sources
identical in color to those that will be used in
the completed installation. When the lighting
system that will be installed is unknown, two
light sources of different spectral character
may be used to examine the samples: one of
the sources should be predominantly blue in

spectral distribution, such as a daylight fluo-

rescent lamp, and the other predominantly

red, such as an incandescent lamp.

Incandescent Sources

Incandescent lamps emit energy in a smooth

curve beginning with a small amount of deep-

blue radiation in the near ultraviolet range

and increasing into the deep-red portion of

the spectrum (color plate 13). The color of

incandescent light is warm in tone, with most

of the energy concentrated in the red and

yellow range. Although this “white” light is

COLOR

Figure 4.2Amenity Curve, based on a pilot study by A. A. Kruithof, 1941.