The ortho's assistant said that the major staining culprits were mustard, curry, and red wine. I love all these things, so it's going to be tough to say no to them, but doable. Lesser offenders (in terms of staining potential) include coffee and tea.
What I'm really having a hard time with is the thought of giving up coffee. I can live w/o a pot a day, but not even a cup first thing in the morning? I could become a threat to myself and others

Has anyone been able to drink a moderate amount of coffee and keep their powerchains white? Maybe if I brush right afterwards?
Failing all of that (she said in desperation), does anyone know if green tea stains?
As ever, thanks in advance for your thoughts.