wiring in multifunction speedometer

[GLS062866]

I have a multifunction speedometer (6Y5-83500-A0-00) and i am asking which colored wire connected to the fuel sender. I have seen diagrams that a solid white is used and others that say use the white/blue wire. Which is correct? If I use the solid white then what is the white/blue used for? If I use the white/blue what is the solid white used for?
Also can a GPS by used with this gauge to get speed instead of water pressure?

thanks,
GLS

[boats.net]

White wire is for USA style fuel senders. No can not connect to GPS for speed.

[GLS062866]

this sounds like a dumb question but how do you tell which one I have? You said USA style. What other types are out there? This is on a 17ft Scout so is it safe to assume that it is a USA style? The white with blue strip is used for senders other than USA style?
thanks,
GLS