What color are electrons? originally appeared on Quora: the knowledge sharing network where compelling questions are answered by people with unique insights. Answer by Jerzy Michał Pawlak, PhD in High Energy Physics, on Quora: Let’s start with the question “how do we perceive color?” Our eyes, when receiving light, measure not only its intensity, but also very roughly, its wavelength. We seldom see really monochromatic light; usually what we see is a mixture of different wavelengths. Our eyes have evolved to perceive one particular mixture, in which proportions of various wavelengths are similar, as in natural sunlight, as neutral or “white.” Now, if you look at some object that reflects or scatters