Seeing new colours with new photoreceptors
Each human optic nerve contains between 770,000 and 1.7 million nerve fibers, So it will be beyond human grasp to swap eyes in the near future, genetic eye and optic fiber development has to happen in the womb. Eye grafts require some kind of neural nanotechnology which is probably multiple generations away. 

If you replace a human photoreceptor with another color, the result is: un-demonstrated/unknown.

Genetically engineered photoreceptor color swap (swap UV and blue)  which sends impulses to the same optic nerves as the previous color, may, and probably would work fine. 

If you switch one eye to CMY and keep the other as RGB, it should have a usable result. 

If you switch both eyes to CMY it's fine too, we would expect that there would be a fair vision perception, perhaps equivalent to RGB in clarity. 

If you design a fetus with 4-5 photoreceptors and let it develop normally, It would have an unknown result. Perhaps the baby would have augmented vision, perhaps troubled. It's not know and many scientists would love to know the result. 

I'd wager that a human with 4-5-6 colors of photoreceptors can be genetically engineered to see, within our lifetime.