I hope someone develops a way for people to see the opposite of what they have some day. I think it would be a mind blowing experience to see the world in different colours. I have always loved the theory that we all actually love the same colour, but no one really sees the world in the same colours so as a result we all have different names for it.
Probably wouldn't be that tough what with Oculus Rift VR-type stuff. You mount a camera on the front of the Rift, have it invert the colors or whatever, then pipe it into your view. Not perfect, but could be done today.