Greg, A nice pictorial explanation of the colour-blind problem can be seen
here.
It also give you a very good idea what the inside of a UK plug looks like if you haven't seen one before. The power cord always exits downwards making for a neat appearance in a room, especially a kitchen - the appliance can back right up to the plug.
I will note that black/white/green achieves the same colour-blind distinction. Just don't add red or orange to the mix!
