Yes and yes. Standard NIR illuminators are everywhere. You would need context to distinguish that it's not green except I suspect it's a very specific green so your brain may be able to do interesting things with that knowledge.

Edit: looking at the emission charts, it's a wider bandwidth than I expected, not sure how well the brain would be able to use the specificity of the green.

Things that are normally just cool enough to not emit significant visible would suddenly be visible. It's far far from the standard 7-14um thermal IR, but would be... well.. downright awesome.

It might be possible to design a mixture of these to generate "impossible colors".

>It might be possible to design a mixture of these to generate "impossible colors".

Since they just convert light between frequencies, they won't show you any colors you couldn't see by illuminating your retina with the output frequencies the old fashioned way.

Agreed, I'm referring to type 2: https://en.wikipedia.org/wiki/Impossible_colors

If the treatment changes just green receptors then IR green would activate just those, but real green would activate all three receptors to various degrees. So maybe you could tell real green from IR green.