Red and Green should never be seen

This chilli plant has been in our porch for a while. We brought it in to the kitchen, so that it was easier to nip one off for cooking and the green chillis have turned red within a few days. Amazing the difference a little bit of heat makes.

As nature is full of the most wonderful red and green combinations. I have always wondered about the saying Red and Green should never be seen. (Which I know the second line of as Except on an Irish Queen but have heard a few variations).

Anyone know the origins of this saying? And what the original version was?