> Color is a perceptual phenomenon which happens in people’s brains, and is several steps removed from light spectra, involving several types of adaptation and

> Color is a perceptual phenomenon which happens in people’s brains, and is several steps removed from light spectra, involving several types of adaptation and varying from person to person and context to context. That's one way it's commonly used. But in some contexts color is also used to mean spectral distribution. That's the whole issue. It's the same as "If a tree falls in a forest and no one is around to hear it, does it make a sound?". The whole conundrum only arises due to overloaded meanings in many languages.