But wavelengths are a property of the waves that exist in the wild, while color is a property of our brains interpreting those wavelengths. There's a fundamental difference there: one could say that wavelengths exist independently of the existence of conscious beings (even if no one measures them), while colors only exist if a conscious being can capture photons and has a certain brain system that can interpret those photon's wavelengths.
There's a common abuse of language that the ancestor comment uses, where we also use the names of colors for the wavelength of the pure light that we perceive them as; perhaps they could have been more specific about that. Hence because of this abuse of terminology we have words like infrared and ultraviolet to refer to spectra beyond human color perception, but are so called for their relation to the particular pure wavelengths that we perceive as red and violet.
Wavelength measures something in the wild. Whatever that something is, colour (and thus purple) offers a different way to measure the same thing. While the measuring unit differs, the fundamentals are the same.
interesting, so you're saying wavelengths are also a construct of the human mind (handed with a device to measure them). Maybe then the Buddha was right when he said "form is emptiness"? Which would mean there's no way that something really is independent of the way of looking at it, that things are empty, there are only ways of looking...
