A note on the possibility of explaining why a color cannot be both red and green.

To provide a neurophysiological basis for the opponent nature of color vision it has been previously argued that a color cannot be both red and green because color-opponent neurons cannot respond to both red and green at the same time. The present analysis shows that such arguments hinge on the possibility of excluding statements of the kind "a color can be both red and green." For an empirical fact to exclude such statements, these statements would have to be meaningful. However, statements like "a color is both red and green" are not meaningful and are not allowed in our language. Thus, the properties of neurons are not in a position to exclude the possibility of "a color that is both red and green." This means that this attempt to establish a neurophysiological basis for opponent colors is flawed.