The negative
afterimage example provides support for the opponent process theory of color vision. This theory was
first proposed by Ewald
Hering in 1878. The author argued that white
and yellow are not composed sensations of color, but they were as pure or primary as the red, green and blue. He proposed that the nature of color vision was due to the pairing of
color sensations, which would operate through opposing processes . That is , each receptor would produce two types of responses antagonistic to each other. When a
member of the pair is stimulated more than his
opponent, then you will see the corresponding superior hue, but are stimulated by the same, they are canceled by being complementary and feeling gray appear, as occurs in the subtractive color mixing
