It's a lot more complicated than RGB buckets, there is a serie of preprocessing cells https://en.wikipedia.org/wiki/Retinal_ganglion_cell https://en.wikipedia.o

It's a lot more complicated than RGB buckets, there is a serie of preprocessing cells https://en.wikipedia.org/wiki/Retinal_ganglion_cell https://en.wikipedia.org/wiki/Retinal_ganglion_cell before the image "signal" is further processed by the visual cortex. Another species could have the exact same "buckets" configuration and perceive color differently if the ganglionic layer is connected differently to those buckets.