surface appear red, because only red wave-
lengths of light are reflected toward the eye.
All other wavelengths are absorbed.
If the tomato is lighted with a green
source, however, it will appear dark gray
because no red energy is available to be
reflected. The eye can see only the colors of
a surface that are present in the source of
illumination (color plate 10).
Because the proportion of colors in
“white” light varies, what we call white light
is a broad category. Within this category, the
most common variations are described as
“warm” or “cool.” A warm white light empha-
sizes the long (high nm) end of the spec-
trum, with hues of yellow through orange to
red. Warm light sources that emphasize
these hues include the sun andincandes-
cent, tungsten-halogen,andhigh-pressure
sodiumlamps. Conversely, a cool white light
source emphasizes the short (low nm) end of
the spectrum, with hues of blue through
green to yellow. Cool light sources that
emphasize these hues include north skylight
and many fluorescent and metal halide
lamps.
Spectral distribution charts, available
from lamp manufacturers, express the rela-
tive color composition of light sources (color
plates 13–17 and 19–31). Because these
charts are of limited practical value in pre-
dicting how colors will appear, simplified sys-INTERIOR LIGHTING FOR DESIGNERS
Figure 4.1To provide accurate color rendition, the light source must emit the wavelengths that the object reflects.