[chillingeffect]

Seems like it could be expanded to a total of 6 cones, three per eye? what a time to be alive :)

[jcl]

Curiously, it seems hexachromacy is already within the realm of biological possibility for human females.

https://en.wikipedia.org/wiki/Pentachromacy#Animals_that_are...

[ConceptJunkie]

I'm holding out for dodecachromacy like the mantis shrimps have.

https://en.wikipedia.org/wiki/Mantis_shrimp#Eyes