[xnx]

Related: Stare at the dot here for ~1 minute: https://dynomight.net/img/colors/eclipse-(255,0,0)-(0,170,85...

From: https://news.ycombinator.com/item?id=44594808

[ProllyInfamous]

Many more such example on this wikipedia page:

<https://en.wikipedia.org/wiki/Impossible_color>

My personal favorite is "Hyperbolic Red" – which is the brightest pink you'll never actually see in nature.

[hankbond]

that is quite the green.

[aaroninsf]

That link is fantastic.