When we look at a painting, or open a box of pencils, we call every shade and tone we see “color”: black and white, however, not appearing in the light spectrum, may not be considered colors: white is the sum of all the reflected lights, black is what we see when the light disappears.
In scientific terms, color is the range of visible light that humans can see and which we distinguish by evaluating different wavelengths. And so far, everything is clear: the problem with this approach is that some colors considered important for cataloging the world – or for example in art – are completely absent: among these, black and white.
If color is just what physics describes, i.e. the visible spectrum of light waves, then black and white are excluded and do not count as true physical colors. This is because they are not technically present in the spectrum: they are the result of the mixing of wavelengths of light by our eyes. Specifically, white is what we see when all wavelengths of light are reflected from an object, while black is what our eyes see in a space that reflects very little light (which is why upon entering a room with the lights off, everything is black).
If, however, we include in the definition of “color” all the ways in which human eyes process light, and therefore also its absence, then black and white have every right to be included among the colors. This definition, in reality, helps us more to understand the world: if we consider colors only those that appear in the spectrum, then not even magenta would be, nor would brown, pink and all the other colors that do not have a specific wavelength, but are produced by a mixture of different wavelengths.
