literal form, the inversion refers to reversing the mapping between color expe-
riences and the physical spectrum of wavelengths of light, as though the rain-
bow had simply been reversed, red for violet (and vice versa) with everything
in between being reversed in like manner. The claim of the inverted spectrum
argument is that no one would ever be able to tell that you and I have different
color experiences.
This particular form of color transformation would not actually wor kas in-
tended because of the shape of the color solid (Palmer, 1999). The color solid is
asymmetrical in that the most saturated blues and violets are darker than the
most saturated reds and greens, which, in turn, are darker than the most satu-
rated yellows and oranges (see figure 1.1A). The problem this causes for the
literal inverted spectrum argument is that if my hues were simply reversed,
your experience of yellow would be the same as my experience of blue-green,
and so you would judge yellow to be darker than blue-green, whereas I would
do the reverse. This difference would allow the spectral inversion of my color
experiences (relative to yours) to be detected.
This problem may be overcome by using more sophisticated versions of
the same color transformation argument (Palmer, 1999). The most plausible is
Figure 1.
Sophisticated versions of the inverted spectrum argument. Transformations of the normal color
solid (A) that would not be detectable by behavioral methods include (B) red-green reversal, which
reflects each color about the blue-yellow-black-white place; (C) the complementary transformation,
which reflects each color through the central point; and (D) blue-yellow and black-white reversal,
which is the combination of both the two other transformations (B and C). (After Palmer, 1999.)
Visual Awareness 13