Color is among the most challenging aspects of our experience to describe. Spectrophotometers and colorimeters can quantify light waves, yet their measurements have little impact on our feeling for color. As the philosopher Zeno Vendler put it, “Vincent van Gogh loved the color yellow—and certainly not because of its wavelength.” Color is infamous for its variability in language and perception. How can we know that what we are seeing is the same as what someone else sees? How can we separate what we are seeing from the thing itself? Or, as Ludwig Wittgenstein asked in his Remarks on Colour, “Where do we draw the line here between logic and experience?” In the Remarks, written the year before his death in 1951, the philosopher’s thoughts about color invariably lead back to the study of philosophy. What things are knowable? How are they known? What can be determined through philosophical reasoning? Wittgenstein reflected, “Colors are a stimulus to philosophizing.”
Color can reveal the variety of experience in a way that few other subjects can. Vision, whether described in language or represented in paintings or film or virtual reality, is the quotidian version of locked-in syndrome. In literature and poetry, the personal nature of color perception often serves as a metaphor for other sweeping failures of communication. In everyday conversations, those stumbling, destabilizing references to a blue sweater (it’s actually black) or a green car (it’s blue, in fact) are both forgettable and earth-shattering. For some philosophers, the experience of color is most similar to that of pain: an internal state that resists quantification. But who wouldn’t rather philosophize about azure instead of aches and pains?
In the Remarks, Wittgenstein briefly considered color in photography, though he was quick to note that his example was “not a color photograph.” For someone born in 1889, color photography was still an exception to the rule. Wittgenstein describes but does not name an image of a scene in a machine shop. In it, he saw “a man with dark hair and a boy with slicked-back blond hair standing in front of a kind of lathe, which is made in part of castings painted black.” “What does it mean,” he asks, “that hair looks blond in a photograph?” He identifies several types of metal in the shop—the painted castings, galvanized wire, iron, and zinc, which all seem truthfully represented by shades of gray in the photograph. But the blond hair confounds him: “How does it come out that it looks this way as opposed to our simply concluding that this is its color?” Wittgenstein seems to immediately perceive color in the black-and-white photograph, rather than logically deducing that the light-toned hair must be blond.