Ah ha, Florida, like me you fight tarnish like the plague it is!
First let me tell you that there is no such thing as "white" gold naturally. For a full discussion of this fact, I'd like to refer back to this tip from November 2009: What Is White Gold
? (read the comments, too!). So no, I don't think using white gold wire is your answer.
Now on to your other comment. I wonder if you are polishing your Argentium wire with a cloth while you work with it? I have used Argentium for more than 5 years now and I love its bright, white color. To me, when both kinds of wire are polished and clean, lying side-by-side, sterling silver has a gray tint when placed next to Argentium that is a bright white. Anyone else?
Answer contributed by Dale "Cougar" Armstrong