On the high-wavelength side of things, we see almost-infrared as reddish, with a slight tinge of magenta. On the low side, we see violet fading into the same magenta color. Why is that?
You can see it clearly on any hue chart. There's an unbroken flow from one to the other, even though the wavelengths are literally as far apart as they can be while still remaining visible.
I understand that color vision is limited due to several biological factors(cone receptivity, absorption, etc), but why do the colors on both side fade into each other? Is it just our brain making things "neat" and continuous?