???

Due to downsizing I find myself back in the job market.  I have a few interviews lined up and was wondering if a white dress shirt is the only appropriate option for a man?

Indeed, you should keep your interview shirts on the plain side. You want the interviewer focused on you, not your shirt. This doesn't mean that a white is your only option.  
Simply put, just stay away from bold colors, try a light blue, pale yellow, lavender, or a mint green all of which are perfectly acceptable and would look great.  Keep the shirts patterns subdue, subtle and on the minimal side. And for the love of God make sure that you have a shirt and tie combination that complement one another as well as your personality.