It is possible to see something close (how close I don't know) by saturating the S & M cones instead of avoiding them. Wikipedia refers to these as 'chimerical colors':
Having read this comment from today detailing variance in the default Windows 95 background (https://news.ycombinator.com/item?id=49329282), I'm imagining Olo would be your wallpaper if "257 colors" could be supported.
I've always taken it to be that the color is unique to the situation/viewer -- a sort of pearlescent void-color that can't be described in any known language, but which just Is. More a physical phenomenon than an actual color, but distinctly hued somehow.
https://en.wikipedia.org/wiki/Impossible_color#Chimerical_co...
https://en.wiktionary.org/wiki/octarine
I suspect many animals experience color quite differently, including seeing infrared/ultraviolet, etc.
Basically equivalent to
source: trust me bro