[upofadown]

If you go out and buy LEDs for use in a traffic signal in North America, you will have to specify the colour as "cyan". That is because the monochromatic wavelength sits in the place between green and blue. So the same sort of situation in naming occurs in that part of the world too. You can call the colour green, but you could just as legitimately call the colour blue. It really just ends up being a convention.